http://www.rssboard.org/rss-specification 720 https://escholarship.org/uc/ucsd_postprints/rss Recent eScholarship items from UC San Diego Previously Published Works Fri, 15 May 2026 07:02:47 +0000 https://escholarship.org/uc/item/42v7c2c7 With more than half the global population on social media, there is a critical need to understand how to engage it in a way that improves rather than worsens user well-being. Here, we show that positive empathy is a promising tool. Participants who received brief positive empathy instructions before 10 min of browsing their own Instagram feed showed greater affective well-being (Studies 1-4) and life satisfaction (Study 4) at posttest relative to participants who were instructed to browse as usual. The positive empathy intervention showed an average effect size on well-being of about a quarter of a standard deviation (mean Cohen's <i>d</i> = 0.25). We included unique active control groups in each study. We found using positive empathy on social media was about as beneficial to well-being as watching a nature video (Study 1, N = 298) and was better than instructions to focus on positive content (Study 2, <i>N</i> = 302), empathize with all emotions (Study 3, <i>N</i> = 301), or... https://escholarship.org/uc/item/42v7c2c7 Thu, 14 May 2026 00:00:00 +0000 Depow, Gregory John https://orcid.org/0000-0001-9995-4143 de Mello, Victoria Oldemburgo Inzlicht, Michael https://escholarship.org/uc/item/1rr9h3tk Abstract. This paper presents a comprehensive overview of the Coupled Model Intercomparison Project Phase&nbsp;7&nbsp;(CMIP7) request for data pertaining to Earth systems science, and provides justification for the resources needed to produce this data. Topics within the CMIP7 Earth System&nbsp;(CMIP7-ES) theme centre around tracking of flows of energy, carbon, water and other fluxes across domains, and constraining feedbacks between these cycles and the climate system. These topics are summarized in this paper as scientific “opportunities” describing specific model intercomparison experiments and use cases for next-generation Earth System Model&nbsp;(ESM) output. These opportunities were submitted by modelling groups and scientific consortia following an extended public consultation process. Contained within each opportunity are requests for groups of Climate &amp; Forecasting&nbsp;(CF) variables, which are bundled into variable groups representing all data required to address... https://escholarship.org/uc/item/1rr9h3tk Thu, 14 May 2026 00:00:00 +0000 McPartland, Mara Y Lovato, Tomas Koven, Charles https://orcid.org/0000-0002-3367-0065 Wilson, Jamie D Turner, Briony Petrik, Colleen M https://orcid.org/0000-0003-3253-0455 Licón-Saláiz, José Li, Fang Lhardy, Fanny Kinney, Jaclyn Clement Kawamiya, Michio Hassler, Birgit Gillett, Nathan P Fall, Modou Noreyni Danek, Christopher Brierley, Chris M Bastos, Ana Andrews, Oliver https://escholarship.org/uc/item/1h04s67g Approximately 200 million people consume cannabis annually, with a significant proportion of them using it chronically. Using experience sampling, we describe the effects of chronically getting high on emotions, motivation, effort, and self-regulation in everyday life. We queried chronic users ( N = 260) 5 times per day over 7 days (3,701 observations) to assess immediate effects of getting high and longer term, between-person effects. Getting high was associated with more positive emotions and fewer negative emotions. Contrary to stereotypes, we observed minimal effects on motivation or objective effort willingness. However, getting high was associated with lower scores on facets of conscientiousness. Surprisingly, there was no evidence of a weed hangover. Relative to less frequent users, very frequent users exhibited more negative emotions dispositionally, but they were more motivated. They also reported less self-control and willpower. As attitudes about cannabis are changing,... https://escholarship.org/uc/item/1h04s67g Thu, 14 May 2026 00:00:00 +0000 Inzlicht, Michael Sparrow-Mungal, Taylor Bridget Depow, Gregory John https://orcid.org/0000-0001-9995-4143 https://escholarship.org/uc/item/1bk2w52m <i>Pseudomonas putida</i> is a gram-negative bacterial species increasingly utilized in biotechnology due to its robust growth, ability to degrade aromatic compounds, solvent tolerance, and genetic tractability. In this study, we report a comprehensive multi-strain analysis of 164 <i>P. putida</i> strains based on the reconstruction of a pan<i>-</i>putida metabolic network and the formulation of strain-specific genome-scale metabolic models (GEMs). We performed whole-genome sequencing and hybrid assembly for 40 strains, contributing a ~8% increase to the available genomic data for <i>P. putida</i>. Furthermore, high-throughput phenotypic profiling using the Biolog phenotype microarray system for 24 strains on 190 unique carbon sources, along with 15 aromatic compounds not present on Biolog plates, yielded 4,920 unique strain-phenotype measurements. These data were leveraged to curate GEMs for 24 representative strains, including a refined model for strain KT2440, which comprised... https://escholarship.org/uc/item/1bk2w52m Thu, 14 May 2026 00:00:00 +0000 Mueller, Joshua Krishnan, Jayanth Wei, Qixing Hefner, Ying Monk, Jonathan M Verkler, Hans Tibocha-Bonilla, Juan D Ayala, Anthony Palsson, Bernhard O https://orcid.org/0000-0003-2357-6785 Feist, Adam M https://orcid.org/0000-0002-8630-4800 Niu, Wei https://escholarship.org/uc/item/0qp9m9t3 Chimallivirus bacteriophages enclose their replicating genomes in a protein-based compartment termed the phage nucleus. While the phage nucleus segregates phage DNA from host immune proteins, it is not known if additional factors are required to protect against DNA-targeting host defenses. Here, we identify a chimallivirus-encoded DarG2-like antitoxin that localizes to the phage nucleus and provides protection against phage-targeting DarTG2 toxin-antitoxin systems. This protein, which we term AdfM (anti-darT factor macro), contains a macrodomain and removes DarT2-mediated ADP-ribose modifications from DNA. In the absence of AdfM, DarT2 modifies phage DNA and restricts chimallivirus replication despite being largely excluded from the phage nucleus. Increasing the nuclear concentration of DarT2 while decreasing the nuclear concentration of AdfM reduces phage replication. These results show that the phage nucleus is insufficient to completely protect the chimallivirus genome from... https://escholarship.org/uc/item/0qp9m9t3 Wed, 13 May 2026 00:00:00 +0000 Morgan, Chase J Rani, Phoolwanti Deep, Amar Liu, Rui Basu, Dwaipayan Chambers, Lydia R Li, Ying-Xing Levine, Makaela Hsieh, Kendall Adler, Benjamin A Birkholz, Erica Doudna, Jennifer A Villa, Elizabeth https://orcid.org/0000-0003-4677-9809 Corbett, Kevin D https://orcid.org/0000-0001-5854-2388 Pogliano, Joe https://escholarship.org/uc/item/8pf0j51w This paper is the first in a pair presented within the session: Findings from the CFS10 Multi-Hazard Test Program. The emphasis within this article is to, in brevity, describe the scope of a landmark full-scale 10-story cold-formed steel (CFS) framed building tested under multi-hazard (earthquake and fire) scenarios at the UC San Diego 6-DOF Large High-Performance Outdoor Shake Table (LHPOST6). Coined CFS10, this unique building specimen is designed beyond current code height limits, adopting advances in cold-formed steel shear wall detailing, varied construction modalities, and enriched with nonstructural components and systems. The landmark CFS10 building specimen was subjected to extreme multi-hazard (earthquake and fire) loading conditions. This paper sets the framework for presentations to be shared at the Congress, while also aiding in ongoing documentation of findings from the program. https://escholarship.org/uc/item/8pf0j51w Tue, 12 May 2026 00:00:00 +0000 Hutchinson, Tara C Zhang, Jiachen Charlie https://orcid.org/0000-0001-9966-6627 Sorosh, Shokrullah https://orcid.org/0000-0003-2826-9696 Ji, Ruipu https://orcid.org/0009-0008-5879-8875 Rivera, Daniel Zhang, Xianzhao Singh, Amanpreet Rukundo, Fidence Cyizere Eladly, Mohammed M Jones, Harry Karns, Jesse Padgett, Lynn Emberley, Richard Gernay, Thomas Meacham, Brian Schafer, Benjamin W https://escholarship.org/uc/item/7v77b9ds This paper is the second of a set presented within the session: Findings from the CFS10 Multi-Hazard Test Program. The emphasis within this article is to highlight correlations between physical damage to nonstructural components and systems with measured response during a suite of 18 earthquake tests and 2 subsequent fire tests. This damage was documented within a 10-story cold-formed steel-framed building test specimen outfitted with various nonstructural components, including suspended ceilings, architectural finishes, a resilient stair system, windows and doors, pressurized fire sprinkler and gas piping systems, and roof-mounted mechanical equipment. The test building and multi-hazard protocol are described in the session companion paper. This paper provides test observations correlated with measured engineering demand parameters such as floor acceleration, building inter-story drift, or peak local temperature responses and offers related literature emerging from the project.... https://escholarship.org/uc/item/7v77b9ds Tue, 12 May 2026 00:00:00 +0000 Singh, Amanpreet Sorosh, Shokrullah https://orcid.org/0000-0003-2826-9696 Zhang, Xianzhao Zhang, Jiachen https://orcid.org/0000-0001-9966-6627 Rukundo, Fidence Cyizere Eladly, Mohammed Ji, Ruipu https://orcid.org/0009-0008-5879-8875 Rivera, Daniel Padgett, Lynn Meacham, Brian J Gernay, Thomas Emberley, Richard L Schafer, Benjamin W Hutchinson, Tara C https://escholarship.org/uc/item/55f3f6mz Inbred mouse strains are essential to biomedical research, yet accumulating mutations and substrain divergence introduce phenotypic variability that can confound experimental outcomes. This study investigates behavioral differences among 13 inbred mouse substrains: eight C57BL/6 (B6) and five C57BL/10 (B10), bred in-house to control for environmental effects. Female F1 offspring underwent a standardized battery of behavioral assays—open field test (OFT), locomotor response to cocaine (LOCO), fear conditioning (FC), prepulse inhibition (PPI), and the forced swim test (FST)—chosen for their relevance to models of psychiatric and substance use disorders. Significant substrain-specific differences were observed across all behaviors. In the OFT, B6 substrains such as C57BL/6J showed higher activity than others, while B10 substrains exhibited distinct edge-zone preference patterns. Cocaine-induced locomotor stimulation varied significantly among B6 substrains but not among B10. In FC,... https://escholarship.org/uc/item/55f3f6mz Tue, 12 May 2026 00:00:00 +0000 St. Pierre, Celine L Gonzales, Natalia M Sokoloff, Greta Polesskaya, Oksana https://escholarship.org/uc/item/94k7t0zt All-solid-state batteries using sulfur-based positive electrodes (cathodes) offer a cost-effective route to achieve high specific energy. However, low active material utilization and cycle life hinder performance. Here, we demonstrate a positive electrode design that employs sulfide solid-state electrolytes, where a high energy synthesis approach forms a metastable and ionically conductive interphase on the active material surface. This interphase facilitates high active material utilization and contributes capacity with cycling. We also show that tailoring active material particle sizes to the micron-scale improves rate performance and cycling stability. Structural analysis reveals that the substantial volume change of sulfur-based positive electrodes during operation can partially offset that of the negative electrodes, thereby mitigating internal mechanical stress. The combined design principles enable sulfur areal capacities up to 11 mAh cm-2 while maintaining stable cycling... https://escholarship.org/uc/item/94k7t0zt Fri, 8 May 2026 00:00:00 +0000 Cronk, Ashley Wang, Xiaowei Oh, Jin An Sam Ham, So-Yeon Bai, Shuang Ridley, Phillip Chouchane, Mehdi Huang, Chen-Jui Cheng, Diyi https://orcid.org/0000-0003-1616-9209 Deysher, Grayson Yang, Hedi Sayahpour, Baharak Vicencio, Marta Lee, Choonghyeon Lee, Dongchan Song, Min-Sang Jang, Jihyun Lee, Jeong Beom Meng, Ying Shirley https://orcid.org/0000-0001-8936-8845 https://escholarship.org/uc/item/8jk2j49r Preliminary Evidence that Combination Oral Contraceptive Use in Young Adult Women Is Associated with the Endocrine Stress Response to High-Dose Alcohol https://escholarship.org/uc/item/8jk2j49r Fri, 8 May 2026 00:00:00 +0000 Anthenelli, Robert M https://orcid.org/0000-0002-6612-1126 Momper, Jeremiah Pharm.D Suhandynata, Raymond Henrickson, Cassandra A McKenna, Benjamin S https://orcid.org/0000-0002-5607-6376 https://escholarship.org/uc/item/9vj75117 Motivated by puzzling results of recent experiments, we re-examine the response of a weakly pinned two-dimensional Wigner crystal to a uniform AC electric field. We confirm that at some disorder and magnetic field dependent frequency ω-p$/, an inhomogeneously broadened absorption line emerges. Although the line is conventionally broad in zero magnetic field, in strong fields it appears as a sharp resonance whose width is related to the density of states in the low-frequency tail of the zero-field phonon spectrum. This behavior originates due to the long-range Coulomb interactions. https://escholarship.org/uc/item/9vj75117 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Huse, DA https://escholarship.org/uc/item/9pj4d4zt We study surface plasmons in minimally-twisted gapped bilayer graphene that contains a triangular network of partial dislocations (or AB-BA domain walls) hosting topologically protected one-dimensional electronic states. We show that this system behaves as a plasmonic crystal and we calculate its band structure by solving classical equations of motion for charge dynamics on the network links with impedance boundary conditions at the network nodes. The plasmon dispersion exhibits several notable features such as multiple gapless branches, flat bands, and dissipationless modes at high-symmetry points. We compare our network-based formalism with the conventional random phase approximation and discuss when each approach is valid. Calculations of plasmon waves launched by local scatterers are presented to simulate terahertz nano-imaging experiments. https://escholarship.org/uc/item/9pj4d4zt Thu, 7 May 2026 00:00:00 +0000 Vermilyea, Brian S Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/9nz4308p Can A Neural Network Hear the Shape of A Drum? https://escholarship.org/uc/item/9nz4308p Thu, 7 May 2026 00:00:00 +0000 Zhao, Yueqi Fogler, Michael M https://escholarship.org/uc/item/9f2183bs The ground-state energy and the density correlation function of the electron liquid in a thin one-dimensional wire are computed. The calculation is based on an approximate mapping of the problem with a realistic Coulomb interaction law onto exactly solvable models of mathematical physics. This approach becomes asymptotically exact in the limit of a small wire radius but remains numerically accurate even for modestly thin wires. https://escholarship.org/uc/item/9f2183bs Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/9br6f2vk We propose the theory of transport in a gate-tunable graphene p-n junction, in which the gradient of the carrier density is controlled by the gate voltage. Depending on this gradient and on the density of charged impurities, the junction resistance is dominated by either diffusive or ballistic contribution. We find the conditions for observing ballistic transport and show that in existing devices they are satisfied only marginally. We also simulate numerically the trajectories of charge carriers and illustrate challenges in realizing more delicate ballistic effects, such as Veselago lensing. https://escholarship.org/uc/item/9br6f2vk Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Novikov, DS Glazman, LI Shklovskii, BI https://escholarship.org/uc/item/98v0z3k1 Hopping transport in a one-dimensional system is studied numerically. A fast algorithm is devised to find the lowest-resistance path at arbitrary electric field. Probability distribution functions of individual resistances on the path and the net resistance are calculated and fitted to compact analytic formulas. Qualitative differences between statistics of resistance fluctuations in Ohmic and non-Ohmic regimes are elucidated. The results are compared with prior theoretical and experimental work on the subject. https://escholarship.org/uc/item/98v0z3k1 Thu, 7 May 2026 00:00:00 +0000 Rodin, AS Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/9604v1m0 Low frequency dynamics of disordered XY spin chains and pinned density waves were studied. The difficulty of the problem arose because of strong nonperturbative disorder effects at low frequencies and large length scales. It was found that with the decrease in the frequency, the relevant excitations changed from localized spin waves to two-level systems to soliton-antisoliton pairs. https://escholarship.org/uc/item/9604v1m0 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/8q86326w The dependence of hopping conductance on temperature and voltage for an ensemble of modestly long one-dimensional wires is studied numerically using the shortest-path algorithm. In a wide range of parameters this dependence can be approximated by a power law rather than the usual stretched-exponential form. The relation to recent experiments and prior analytical theory is discussed. https://escholarship.org/uc/item/8q86326w Thu, 7 May 2026 00:00:00 +0000 Rodin, AS Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/8k46h6x5 By using high-magnetic fields (up to 60 T), we observe compelling evidence of the integer quantum Hall effect in trilayer graphene. The magnetotransport fingerprints are similar to those of the graphene monolayer, except for the absence of a plateau at a filling factor of ν=2. At a very low filling factor, the Hall resistance vanishes due to the presence of mixed electron and hole carriers induced by disorder. The measured Hall resistivity plateaus are well reproduced theoretically, using a self-consistent Hartree calculations of the Landau levels and assuming an ABC stacking order of the three layers. https://escholarship.org/uc/item/8k46h6x5 Thu, 7 May 2026 00:00:00 +0000 Kumar, A Escoffier, W Poumirol, JM Faugeras, C Arovas, DP Fogler, MM https://orcid.org/0000-0001-8239-7221 Guinea, F Roche, S Goiran, M Raquet, B https://escholarship.org/uc/item/8dn5q3k2 Many of the existing electrochemical catalysts suffer from poor selectivity, instability, and low exchange current densities. These shortcomings call for a comprehensive exploration of the catalytic processes at the fundamental nanometer length scale levels. Here we exploit infrared (IR) nanoimaging and nanospectroscopy to directly visualize catalytic reactions on the surface of Cu2O polyhedral single crystals with nanoscale spatial resolution. Nano-IR data revealed signatures of this common catalyst after electrochemical reduction of carbon dioxides (CO2). We discuss the utility of nano-IR methods for surface/facet engineering of efficient electrochemical catalysts. https://escholarship.org/uc/item/8dn5q3k2 Thu, 7 May 2026 00:00:00 +0000 Ni, GX Chen, S Sunku, SS Sternbach, A McLeod, AS Xiong, L Fogler, MM https://orcid.org/0000-0001-8239-7221 Chen, G Basov, DN https://escholarship.org/uc/item/83w9470x We study the two-probe transport in a long narrow channel of two-dimensional electron liquid (a quantum wire) in a strong magnetic field normal to the plane. The wire is split into alternating parallel strips of compressible and incompressible liquids. When the temperature is not too low, in every transverse cross section of the wire the electrochemical potential is different in different compressible strips but is uniform within each strip. The equilibration rate between two neighboring compressible strips falls off exponentially with the distance between them (the width of the separating incompressible strip). Assuming a parabolic confinement potential and small disorder potential, we find the magnetic-field dependence of the strip widths. Using only this dependence, we calculate the shape of the magnetoresistance peaks. We show that the low-field sides of these peaks are much steeper than the high-field sides, in agreement with recent experimental data. https://escholarship.org/uc/item/83w9470x Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/80f70057 An ingenious experiment has probed the collective response of the quantum Hall stripe phase. https://escholarship.org/uc/item/80f70057 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/7z67s57k Electric double-layer supercapacitors (SCs) are promising devices for high-power energy storage based on the reversible absorption of ions into porous conducting electrodes. Graphene is a particularly good candidate for the electrode material in SCs due to its high conductivity and large surface area. In this paper, we consider SC electrodes made from a stack of graphene sheets with randomly inserted spacer molecules. We show that the large volumetric capacitances C≳100F/cm3 observed experimentally can be understood as a result of collective intercalation of ions into the graphene stack and the accompanying nonlinear screening by graphene electrons that renormalizes the charge of the ion clusters. https://escholarship.org/uc/item/7z67s57k Thu, 7 May 2026 00:00:00 +0000 Skinner, Brian Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/7x60m1bs We compare the energies of the Laughlin liquid and a charge density wave in a weak magnetic field for the upper Landau-level filling factors νN= and . The charge-density-wave period has been optimized and was found to be ≃3.3Rc, where Rc is the cyclotron radius. We conclude that the optimal charge density wave is lower in energy than the Laughlin liquid for the Landau-level numbers N⩾2 at νN= and for N⩾3 at νN=. This implies that the quantum Hall plateaus cannot be observed for N⩾2, in agreement with the experiment. https://escholarship.org/uc/item/7x60m1bs Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Koulakov, AA https://escholarship.org/uc/item/7x02b766 We present a controlled method for computing the exchange coupling in strongly correlated one-dimensional electron systems. It is based on the asymptotically exact relation between the exchange constant and the pair-correlation function of spinless electrons. Explicit results are obtained for thin quantum rings with realistic Coulomb interactions, by calculating this function via a many-body instanton approach. https://escholarship.org/uc/item/7x02b766 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Pivovarov, Eugene https://escholarship.org/uc/item/7w61h4wf Artifact free time resolved near-field spectroscopy https://escholarship.org/uc/item/7w61h4wf Thu, 7 May 2026 00:00:00 +0000 Sternbach, AJ Hinton, J Slusar, T McLeod, AS Liu, MK Frenzel, A Wagner, M Iraheta, R Keilmann, F Leitenstorfer, A Fogler, M https://orcid.org/0000-0001-8239-7221 Kim, H-T Averitt, RD Basov, DN https://escholarship.org/uc/item/7tv517g9 We show that a quantum Hall bilayer with the total filling nu = 1 should exhibit a dynamical regime similar to the flux flow in large Josephson junctions. This analogy may explain a conspicuous peak in the interlayer tunneling conductance [Phys. Rev. Lett. 84, 5808 (2000)]. The flux flow is likely to be spatiotemporally chaotic at low-bias voltage, which will manifest itself through broadband noise. The peak position can be controlled by an in-plane magnetic field. https://escholarship.org/uc/item/7tv517g9 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Wilczek, Frank https://escholarship.org/uc/item/7tq0f472 We propose a dynamical theory of the stripe phase arising in a two-dimensional electron liquid near half-integral fillings of high Landau levels. The system is modeled as a novel type of a smectic liquid crystal with Lorentz force dominated dynamics. We calculate the structure factor, the dispersion relation of the collective modes, and their intrinsic attenuation rate. We show that thermal fluctuations cause a strong power-law renormalization of the elastic and dissipative parameters familiar from the conventional smectics but with different dynamical scaling exponents. https://escholarship.org/uc/item/7tq0f472 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Vinokur, Valerii M https://escholarship.org/uc/item/7r17s93z A long-standing problem of the low-energy dynamics of a disordered XY spin chain is reexamined. The case of a rigid chain is studied, where the quantum effects can be treated quasiclassically. It is shown that, as the frequency decreases, the relevant excitations change from localized spin waves to two-level systems to soliton-antisoliton pairs. The linear-response correlation functions are calculated. The results apply to other periodic glassy systems such as pinned density waves, planar vortex lattices, stripes, and disordered Luttinger liquids. https://escholarship.org/uc/item/7r17s93z Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/7m57k7zq We study a suspended graphene sheet subject to the electric field of a gate underneath. We compute the elastic deformation of the sheet and the corresponding effective gauge field, which modifies the electronic transport. In a clean system the two-terminal conductance of the sample is reduced below the ballistic limit and is almost totally suppressed at low carrier concentrations in samples under tension. Residual disorder restores a small finite conductivity. https://escholarship.org/uc/item/7m57k7zq Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Guinea, F Katsnelson, MI https://escholarship.org/uc/item/7cq3q7m6 Ultrasound of the Rectus Femoris Muscle and Association with Pediatric Liver Failure - Preliminary One-Year Pilot Outcomes Data https://escholarship.org/uc/item/7cq3q7m6 Thu, 7 May 2026 00:00:00 +0000 Chu, C Yu, V Dodge, J Kasturi, S Acharya, P Rigual, D Terrault, N https://escholarship.org/uc/item/77w4444d Abstract Objectives With the success of antiretroviral therapy (ART), people with HIV (PWH) are living longer. As they age, they increasingly face age-related comorbidities, including neurodegenerative conditions. The astrocyte–neuron lactate shuttle (ANLS) is a key mechanism that couples astrocytic glycolysis to neuronal oxidative metabolism, ensuring an adequate energy supply for synaptic activity. Disruption of this system has been implicated in both Alzheimer’s disease (AD) and HIV-associated neurocognitive impairment (HIV-NCI), conditions characterized by some overlapping cognitive deficits yet distinct pathological drivers. Methods We investigated the expression of major ANLS transporters, including glucose transporters (GLUT1, GLUT3) and monocarboxylate transporters (MCT1, MCT2, MCT4), in postmortem frontal cortex from individuals with AD and PWH. There were two HIV cohorts based on viral suppression (suppressed/non-suppressed), and both were stratified by neurocognitive... https://escholarship.org/uc/item/77w4444d Thu, 7 May 2026 00:00:00 +0000 Boustani, Ali https://orcid.org/0000-0001-8146-7574 Laird, Anna Shu, Leeann Sundermann, Erin E Moore, David J https://orcid.org/0000-0002-2199-1662 Rissman, Robert Fields, Jerel A https://escholarship.org/uc/item/76f3p75j We visualized negative refraction of phonon polaritons, which occurs at the interface between two natural crystals. The polaritons-hybrids of infrared photons and lattice vibrations-form collimated rays that display negative refraction when passing through a planar interface between the two hyperbolic van der Waals materials: molybdenum oxide (MoO₃) and isotopically pure hexagonal boron nitride (h¹¹BN). At a special frequency ω₀, these rays can circulate along closed diamond-shaped trajectories. We have shown that polariton eigenmodes display regions of both positive and negative dispersion interrupted by multiple gaps that result from polaritonic-level repulsion and strong coupling. https://escholarship.org/uc/item/76f3p75j Thu, 7 May 2026 00:00:00 +0000 Sternbach, AJ Moore, SL Rikhter, A Zhang, S Jing, R Shao, Y Kim, BSY Xu, S Liu, S Edgar, JH Rubio, A Dean, C Hone, J Fogler, MM https://orcid.org/0000-0001-8239-7221 Basov, DN https://escholarship.org/uc/item/7517b934 In ultrathin wires positioned on high-κ dielectric substrates or nearby metallic gates, electrons can form strongly correlated one-dimensional fluids already at rather high electron densities. The density-density correlation function, charge compressibility, spin susceptibility, and electron specific heat of such fluids are calculated analytically. The results are relevant for transport and thermodynamics of carbon nanotube field-effect transistors and semiconductor quantum wires. https://escholarship.org/uc/item/7517b934 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/712368wm We calculate the probability to find exactly n eigenvalues in a spectral interval of a large random N×N matrix when this interval contains s≪N eigenvalues on average. The calculations exploit an analogy to the problem of finding a two-dimensional charge distribution on the interface of a semiconductor heterostructure under the influence of a split gate. https://escholarship.org/uc/item/712368wm Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/6vj193hb We introduce RGFlow, a deep neural network-based real-space renormalization group (RG) framework tailored for continuum scalar field theories. Leveraging generative capabilities of flow-based neural networks, RGFlow autonomously learns real-space RG transformations from data without prior knowledge of the underlying model. In contrast to conventional approaches, RGFlow is bijective (information-preserving) and is optimized based on the principle of minimal mutual information. We demonstrate the method on two examples. The first one is a one-dimensional Gaussian model, where RGFlow is shown to learn the classical decimation rule. The second is the two-dimensional phi^4 theory, where the network successfully identifies a Wilson-Fisher-like critical point and provides an estimate of the correlation-length critical exponent. https://escholarship.org/uc/item/6vj193hb Thu, 7 May 2026 00:00:00 +0000 Zhao, Yueqi Fogler, Michael M You, Yi-Zhuang https://orcid.org/0000-0003-4080-5340 https://escholarship.org/uc/item/6rd20898 We show that the cyclotron resonance in a two-dimensional electron gas has nontrivial properties if the correlation length of the disorder is larger than the Fermi wavelength: (a) The line shape assumes three different forms in strong, intermediate, and weak magnetic fields. (b) The linewidth collapses at the transition from the intermediate to the weak fields via the motional narrowing mechanism brought about by a dramatic enhancement of the localization length. https://escholarship.org/uc/item/6rd20898 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/6qf6q589 We study current flow around a density inhomogeneity in a two-dimensional electron gas in the presence of a strong magnetic field. The inhomogeneity is parametrized by a power-law tail with an exponent β&gt;2. We show that current and electrochemical potential are exponentially suppressed inside a surrounding area much larger than the geometric size of the perturbation. The corresponding “no-go” radius grows as a certain power of the magnetic field. Residual current and potential exhibit spiraling patterns inside the no-go region. Outside of it, they acquire corrections inversely proportional to the distance, which is known as the Landauer resistivity dipole. The Landauer dipole is rotated by the angle π(1−1/β) with respect to the average electric field. The rotation direction depends on whether the local density is raised or lowered. We also consider the effect of electron viscosity and show that the variation of the no-go radius with magnetic field becomes more rapid if viscosity... https://escholarship.org/uc/item/6qf6q589 Thu, 7 May 2026 00:00:00 +0000 Parashar, P Shubham Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/6dh8b2pn We propose a new detector concept, GraXe (to be pronounced as grace), to search for neutrinoless double beta decay in 136XE. GraXe combines a popular detection medium in rare-event searches, liquid xenon, with a new, background-free material, graphene. In our baseline design of GraXe, a sphere made of graphene-coated titanium mesh and filled with liquid xenon (LXe) enriched in the 136XE isotope is immersed in a large volume of natural LXe instrumented with photodetectors. Liquid xenon is an excellent scintillator, reasonably transparent to its own light. Graphene is transparent over a large frequency range, and impermeable to the xenon. Event position could be deduced from the light pattern detected in the photosensors. External backgrounds would be shielded by the buffer of natural LXe, leaving the ultra-radiopure internal volume virtually free of background. Industrial graphene can be manufactured at a competitive cost to produce the sphere. Enriching xenon in the isotope 136XE... https://escholarship.org/uc/item/6dh8b2pn Thu, 7 May 2026 00:00:00 +0000 Gómez-Cadenas, JJ Guinea, F Fogler, MM https://orcid.org/0000-0001-8239-7221 Katsnelson, MI Martín-Albo, J Monrabal, F Vidal, J Muñoz https://escholarship.org/uc/item/68k0d5zm Magnetoresistance studies of 2D systems are often shaped by the motion of electrons that occupy spatially confined wave functions, such as topological edge modes and disorder-induced bound states. Directly probing how such states form and behave in situ, under applied currents, provides a clear way of connecting microscopic physics to the macroscopic transport response. In this Letter, scanning tunneling potentiometry is used to probe the local, current-induced electrochemical potential of carriers in graphene near circular p-n junctions in an out-of-plane magnetic field ranging from 0 to 1.4 T. These measurements provide detailed information about the motion of carriers at the nanometer scale, revealing how it evolves with increasing field. The electrochemical potential displays distinct patterns, such as dipoles, spirals, and concentric disks in weak, moderate, and high fields, respectively. The size and orientation of these patterns can be used to understand how local carrier... https://escholarship.org/uc/item/68k0d5zm Thu, 7 May 2026 00:00:00 +0000 Krebs, Zachary J Behn, Wyatt A Smith, Keenan J Fortman, Margaret A Watanabe, Kenji Taniguchi, Takashi Parashar, Pathak S Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Brar, Victor W https://escholarship.org/uc/item/66210796 Twisted bilayer graphene as a terahertz plasmonic crystal https://escholarship.org/uc/item/66210796 Thu, 7 May 2026 00:00:00 +0000 Anonymous https://escholarship.org/uc/item/63w472xm Hemolysis and the downstream consequences of cell-free hemoglobin (Hb) and heme contribute to the development of sickle cell disease pulmonary hypertension (SCD-PH). The plasma concentrations of Hb and heme scavenger proteins haptoglobin (Hp) and hemopexin (Hpx) in sickle cell patients are observed to be significantly lower than healthy donors. The unchecked exposure to Hb and heme contribute to vasculopathy and aberrant cardiac function. This is consistent with vascular remodeling co-localized within iron rich macrophages. Based on these observations in patients, we hypothesize that a joint Hb and heme scavenger approach, combining Hp + Hpx as a therapeutic will attenuate hemolysis driven SCD-PH progression in a SCD mouse model. To test the hypothesis, we utilized our validated Berk-SS mouse model of SCD-PH driven by a 10-week moderate hypoxia exposure and weekly subcutaneous administration of Hp + Hpx. At study termination, we analyzed changes in cardiopulmonary iron deposition,... https://escholarship.org/uc/item/63w472xm Thu, 7 May 2026 00:00:00 +0000 Lucero, Melissa J Lisk, Christina Swindle, Delaney Cendali, Francesca Setua, Saini Thangaraju, Kiruphagaran Khan, Alamzeb Pak, David I O'Boyle, Quintin Lu, Shuwei Tolson, Robert Zaeske, Seth Khan, Saqib Rana, Nishant Westover, Natalie Davizon-Castillio, Pavel George, Gemlyn Hassell, Kathryn Nuss, Rachelle Brinkman, Nathan Gentinetta, Thomas Niemeyer, Christy Cabrales, Pedro Palmer, Andre D'Alessandro, Angelo Buehler, Paul W Irwin, David C https://escholarship.org/uc/item/62j6b0tm We report a combined nano-photocurrent and infrared nanoscopy study of twisted bilayer graphene (TBG) enabling access to the local electronic phenomena at length scales as short as 20 nm. We show that the photocurrent changes sign at carrier densities tracking the local superlattice density of states of TBG. We use this property to identify domains of varying local twist angle by local photothermoelectric effect. Consistent with the photocurrent study, infrared nanoimaging experiments reveal optical conductivity features dominated by twist-angle-dependent interband transitions. Our results provide a fast and robust method for mapping the electronic structure of TBG and suggest that similar methods can be broadly applied to probe electronic inhomogeneities of Moiré superlattices in other van der Waals heterostructures. https://escholarship.org/uc/item/62j6b0tm Thu, 7 May 2026 00:00:00 +0000 Sunku, Sai S McLeod, Alexander S Stauber, Tobias Yoo, Hyobin Halbertal, Dorri Ni, Guangxin Sternbach, Aaron Jiang, Bor-Yuan Taniguchi, Takashi Watanabe, Kenji Kim, Philip Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Basov, DN https://escholarship.org/uc/item/6198t535 Hyperbolic Cooper-pair polaritons (HCP) in cuprate superconductors are of fundamental interest due to their potential for providing insights into the nature of unconventional superconductivity. Here, we critically assess an experimental approach using near-field imaging to probe HCP in Bi₂Sr₂CaCu₂O_8+<i>x</i> (Bi-2212) in the presence of graphene surface plasmon polaritons (SPP). Our simulations show that inherently weak HCP features in the near-field can be strongly enhanced when coupled to graphene SPP in layered graphene/hexagonal boron nitride (hBN)/Bi-2212 heterostructures. This enhancement arises from our multilayered structures effectively acting as plasmonic cavities capable of altering collective modes of a layered superconductor by modifying its electromagnetic environment. The degree of enhancement can be selectively controlled by tuning the insulating spacer thickness with atomic precision. Finally, we verify the expected... https://escholarship.org/uc/item/6198t535 Thu, 7 May 2026 00:00:00 +0000 Berkowitz, Michael E Kim, Brian SY Ni, Guangxin McLeod, Alexander S Lo, Chiu Fan Bowen Sun, Zhiyuan Gu, Genda Watanabe, Kenji Taniguchi, Takashi Millis, Andrew J Hone, James C Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Averitt, Richard D Basov, DN https://escholarship.org/uc/item/60q408m9 Activated dissipative conductivity σxx = σ*xxexp(−Δ/T) and the activated deviation of the Hall conductivity from the precise quantization δσxy = σxy −ie2/h= σ*xyexp(−Δ/T) are studied in a plateau range of the quantum Hall effect. The prefactors σ*xx and σ*xy are calculated for the case of a long-range random potential in the framework of a classical theory. There is a range of temperatures T1 ≪ T ≪ T2 where σ*xy = e2/h. In this range σ*xy ≈ (e2/h)(T/T2)80/21 ≪ σ*xx. At large T ≫ T2, on the other hand, σ*xy = e2/h and σ*xx = (e2h)(T2T)10/13 ≪ σ*xy. Similar results are valid for a fractional plateau near the filling factor p/q if charge e is replaced by e/q. https://escholarship.org/uc/item/60q408m9 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Polyakov, DG Shklovskii, BI https://escholarship.org/uc/item/60n1t16g The electron–hole plasma in charge-neutral graphene is predicted to realize a quantum critical system in which electrical transport features a universal hydrodynamic description, even at room temperature1,2. This quantum critical ‘Dirac fluid’ is expected to have a shear viscosity close to a minimum bound3,4, with an interparticle scattering rate saturating1 at the Planckian time,&nbsp;the shortest possible timescale for particles to relax. Although electrical transport measurements at finite carrier density are consistent with hydrodynamic electron flow in graphene5–8, a clear demonstration of viscous flow at the charge-neutrality point remains elusive. Here we directly image viscous Dirac fluid flow in graphene at room temperature by measuring the associated stray magnetic field. Nanoscale magnetic imaging is performed using quantum spin magnetometers realized with nitrogen vacancy centres in diamond. Scanning single-spin and wide-field magnetometry reveal a parabolic Poiseuille... https://escholarship.org/uc/item/60n1t16g Thu, 7 May 2026 00:00:00 +0000 Ku, Mark JH Zhou, Tony X Li, Qing Shin, Young J Shi, Jing K Burch, Claire Anderson, Laurel E Pierce, Andrew T Xie, Yonglong Hamo, Assaf Vool, Uri Zhang, Huiliang Casola, Francesco Taniguchi, Takashi Watanabe, Kenji Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Kim, Philip Yacoby, Amir Walsworth, Ronald L https://escholarship.org/uc/item/5z10j92b Polaritons are quantum mechanical superpositions of photon states with elementary excitations in molecules and solids. The light-matter admixture causes a characteristic frequency-momentum dispersion shared by all polaritons irrespective of the microscopic nature of material excitations that could entail charge, spin, lattice or orbital effects. Polaritons retain the strong nonlinearities of their matter component and simultaneously inherit ray-like propagation of light. Polaritons prompt new properties, enable new opportunities for spectroscopy/imaging, empower quantum simulations and give rise to new forms of synthetic quantum matter. Here, we review the emergent effects rooted in polaritonic quasiparticles in a wide variety of their physical implementations. We present a broad portfolio of the physical platforms and phenomena of what we term <i>polaritonic quantum matter.</i> We discuss the unifying aspects of polaritons across different platforms and physical implementations... https://escholarship.org/uc/item/5z10j92b Thu, 7 May 2026 00:00:00 +0000 Basov, DN Asenjo‐Garcia, Ana Schuck, P James Zhu, Xiaoyang Rubio, Angel Cavalleri, Andrea Delor, Milan Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Liu, Mengkun https://escholarship.org/uc/item/5vh5x1nh We consider a clean two-dimensional electron liquid in a weak magnetic field where N≫1 lower Landau levels are completely filled, while the upper level is only partially filled. Due to a screening by the lower Landau levels, the repulsive interaction between any two electrons at the upper level as a function of the separation between the guiding centers of their cyclotron orbits abruptly drops at the distance of two cyclotron radii. Such a ‘‘box-like’’ component in the interaction potential makes the uniform distribution of the electron density at the upper Landau level unstable, and domains with filling factor equal to one and zero are formed. The shape of domains is studied both analytically and numerically. We show that when the filling factor of the upper Landau level is close to one-half, the domains have the form of parallel stripes alternating with a spatial period close to three cyclotron radii. Away from a small interval around half-filling, a ‘‘bubble’’ phase is more... https://escholarship.org/uc/item/5vh5x1nh Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Koulakov, AA Shklovskii, BI https://escholarship.org/uc/item/5ps6m9g6 Adolescents experience extensive neurocognitive development, with cannabis use potentially impacting developmental trajectories. Here, we comprehensively assess the influence of adolescent cannabis use onset on neurocognitive trajectories and consider how recent delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) may influence neurocognition. We use the large, diverse longitudinal Adolescent Brain Cognitive Development (ABCD) Study dataset, combining self-reported substance use with objective toxicological tests (hair, urine, breath, oral fluid). Longitudinal mixed methods of the full cohort (n = 11,036, ages 9-17; 47% Female/53% Male) investigate time-varying cannabis onset on neurocognitive performance. Primary model covariates include sociodemographics, family history of substance use disorder, prenatal substance exposure, early psychopathology, other substance use, and nesting for participant ID, study site, and family ID. Secondarily, in participants with repeat toxicological... https://escholarship.org/uc/item/5ps6m9g6 Thu, 7 May 2026 00:00:00 +0000 Wade, Natasha E Sullivan, Ryan M Wallace, Alexander L Visontay, Rachel Szpak, Veronica Lisdahl, Krista M Huestis, Marilyn A Gonçalves, Priscila Dib Byrne, Hollie Mewton, Louise Jacobus, Joanna Tapert, Susan F https://orcid.org/0000-0001-7259-6112 https://escholarship.org/uc/item/5mz093x1 We study the charge density distribution, the electric field profile, and the resistance of an electrostatically created lateral p-n junction in graphene. We show that the electric field at the interface of the electron and hole regions is strongly enhanced due to limited screening capacity of Dirac quasiparticles. Accordingly, the junction resistance is lower than estimated in previous literature. https://escholarship.org/uc/item/5mz093x1 Thu, 7 May 2026 00:00:00 +0000 Zhang, LM Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/5k94s6d5 The quantum localization is known to be responsible for the deep conductivity minima of the quantum Hall effect. In this paper we calculate the localization length ξ as a function of magnetic field B at such minima for several models of disorder (“white-noise”, short-range, and long-range random potentials). We find that ξ∝B−α with the exponent α between one and 103, depending on the model. In particular, for the “white-noise” random potential ξ roughly coincides with the classical cyclotron radius. Our results are in agreement with available experimental data. https://escholarship.org/uc/item/5k94s6d5 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Dobin, A Yu Shklovskii, BI https://escholarship.org/uc/item/5dp0j3q5 If bosonic particles are cooled down below the temperature of quantum degeneracy, they can spontaneously form a coherent state in which individual matter waves synchronize and combine. Spontaneous coherence of matter waves forms the basis of a number of fundamental phenomena in physics, including superconductivity, superfluidity and Bose-Einstein condensation. Spontaneous coherence is the key characteristic of condensation in momentum space. Excitons-bound pairs of electrons and holes-form a model system to explore the quantum physics of cold bosons in solids. Cold exciton gases can be realized in a system of indirect excitons, which can cool down below the temperature of quantum degeneracy owing to their long lifetimes. Here we report measurements of spontaneous coherence in a gas of indirect excitons. We found that spontaneous coherence of excitons emerges in the region of the macroscopically ordered exciton state and in the region of vortices of linear polarization. The coherence... https://escholarship.org/uc/item/5dp0j3q5 Thu, 7 May 2026 00:00:00 +0000 High, AA Leonard, JR Hammack, AT Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Kavokin, AV Campman, KL Gossard, AC https://escholarship.org/uc/item/5ch7739t A Mach-Zehnder interferometer with spatial and spectral resolution was used to probe spontaneous coherence in cold exciton gases, which are implemented experimentally in the ring of indirect excitons in coupled quantum wells. A strong enhancement of the exciton coherence length is observed at temperatures below a few Kelvin. The increase of the coherence length is correlated with the macroscopic spatial ordering of excitons. The coherence length at the lowest temperature corresponds to a very narrow spread of the exciton momentum distribution, much smaller than that for a classical exciton gas. https://escholarship.org/uc/item/5ch7739t Thu, 7 May 2026 00:00:00 +0000 Yang, Sen Hammack, AT Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Gossard, AC https://escholarship.org/uc/item/59f7x6t7 We report on infrared (IR) nanoscopy of 2D plasmon excitations of Dirac fermions in graphene. This is achieved by confining mid-IR radiation at the apex of a nanoscale tip: an approach yielding 2 orders of magnitude increase in the value of in-plane component of incident wavevector q compared to free space propagation. At these high wavevectors, the Dirac plasmon is found to dramatically enhance the near-field interaction with mid-IR surface phonons of SiO(2) substrate. Our data augmented by detailed modeling establish graphene as a new medium supporting plasmonic effects that can be controlled by gate voltage. https://escholarship.org/uc/item/59f7x6t7 Thu, 7 May 2026 00:00:00 +0000 Fei, Zhe Andreev, Gregory O Bao, Wenzhong Zhang, Lingfeng M McLeod, Alexander S Wang, Chen Stewart, Margaret K Zhao, Zeng Dominguez, Gerardo Thiemens, Mark Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Tauber, Michael J Castro-Neto, Antonio H Lau, Chun Ning Keilmann, Fritz Basov, Dimitri N https://escholarship.org/uc/item/57r4n3s2 We consider a set of electrostatic problems relevant for determining the real-space structure and the ground-state energy of a two-dimensional electron liquid subject to smooth external potentials. Three fundamental geometries are investigated: an elongated metallic island, an antidot, and a constriction. In the first two cases complete closed-form analytical solutions are obtained, despite the absence of rotational or translational symmetries. These solutions govern the shape and size of large quantum dots, and also the size of the depletion regions and the density profiles around isolated antidots. For the constriction, an exact asymptotical formula for boundary shape is derived and arguments are given in favor of its universality. For the cases where the full analytical solution cannot be obtained, an approximate method is proposed as an alternative. Its accuracy is verified against numerical simulations in a periodic (checkerboard) geometry. https://escholarship.org/uc/item/57r4n3s2 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/5631z4tn The ground state and the transport properties of graphene subject to the potential of in-plane charged impurities are studied. The screening of the impurity potential is shown to be nonlinear, producing a fractal structure of electron and hole puddles. Statistical properties of this density distribution as well as the charge compressibility of the system are calculated in the leading-log approximation. The conductivity depends logarithmically on alpha, the dimensionless strength of the Coulomb interaction. The theory is asymptotically exact when alpha is small, which is the case for graphene on a substrate with a high dielectric constant. https://escholarship.org/uc/item/5631z4tn Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/54x29895 We evaluate the effect of diffraction-limited resolution of the optical system on the estimates of the coherence length of two-dimensional excitons deduced from the interferometric study of the exciton emission. The results are applied for refining our earlier estimates of the coherence length of a cold gas of indirect excitons in coupled quantum wells [S. Yang , Phys. Rev. Lett. 97, 187402 (2006)]. We show that the apparent coherence length is well approximated by the quadratic sum of the actual exciton coherence length and the diffraction correction given by the conventional Abbe limit divided by π. In practice, accounting for diffraction is necessary only when the coherence length is smaller than about one wavelength. The earlier conclusions regarding the strong enhancement of the exciton coherence length at low temperatures remain intact. https://escholarship.org/uc/item/54x29895 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Yang, Sen Hammack, AT Butov, LV Gossard, AC https://escholarship.org/uc/item/51v647wg Screening of a large external charge in graphene is studied. The charge is assumed to be displaced away or smeared over a finite region of the graphene plane. The initial decay of the screened potential with distance is shown to follow the 3∕2 power. It gradually changes to the Coulomb law outside of a hypercritical core whose radius is proportional to the external charge. https://escholarship.org/uc/item/51v647wg Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Novikov, DS Shklovskii, BI https://escholarship.org/uc/item/5064g7tm The resistivity minima of the quantum Hall effect arise due to the localization of the electron states at the Fermi energy, when it is positioned between adjacent Landau levels. In this paper we calculate the localization length ξ of such states at even filling factors ν=2N. The calculation is done for several models of disorder (“white-noise,” short-range, and long-range random potentials). We find that the localization length has a power-law dependence on the Landau level index, ξ∝Nα with the exponent α between one and 103, depending on the model. In particular, for a “white-noise” random potential ξ roughly coincides with the classical cyclotron radius. Our results are in reasonable agreement with experimental data on low and moderate mobility samples. https://escholarship.org/uc/item/5064g7tm Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Dobin, A Yu Shklovskii, BI https://escholarship.org/uc/item/4wn1z5rf Ovulation is triggered by a surge in luteinizing hormone (LH) secretion from the pituitary. The LH surge is itself driven by a surge in GnRH release induced by estrogen positive feedback action in the hypothalamus. While ERα-expressing kisspeptin (Kiss1) neurons in the preoptic area (in mice, the rostral periventricular region of the third ventricle [RP3V]) are proposed to mediate this estrogen positive feedback event, the functional necessity of RP3V-derived kisspeptin for the LH surge has not been directly tested. Here we leveraged Cre/lox technology and the known high co-expression of tyrosine hydroxylase (TH) with Kiss1 in only the RP3V region to generate novel transgenic mice with selective knockout (KO) of the Kiss1 gene in just RP3V neurons (Kiss1RP3V KO mice). In situ hybridization confirmed a significant 70% reduction in cells expressing Kiss1 in the RP3V region, but not in the arcuate nucleus, along with no change in RP3V Th expression. Kiss1RP3V KO females exhibited... https://escholarship.org/uc/item/4wn1z5rf Thu, 7 May 2026 00:00:00 +0000 Puffer, Marina S Yang, Jason Esparza, Lourdes A Rose, Lillian Duong, Viet Radovick, Sally Kauffman, Alexander S https://escholarship.org/uc/item/4g86z73h We analyze the response of bilayer graphene to an external transverse electric field using a variational method. A previous attempt to do so in a recent paper by Falkovsky [Phys. Rev. B 80, 113413 (2009)]10.1103/PhysRevB.80.113413 is shown to be flawed. Our calculation reaffirms the original results obtained by one of us [E. McCann, Phys. Rev. B 74, 161403(R) (2006)10.1103/PhysRevB.74.161403] by a different method. Finally, we generalize these original results to describe a dual-gated bilayer graphene device. https://escholarship.org/uc/item/4g86z73h Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 McCann, E https://escholarship.org/uc/item/4dh582wv Variable-range hopping transport along short one-dimensional wires and across the shortest dimension of thin three-dimensional films and narrow two-dimensional ribbons is studied theoretically. Geometric and transport characteristics of the hopping resistor network are shown to depend on temperature T and the dimensionality of the system. In two and three dimensions, the usual Mott law applies at high T where the correlation length of the network is smaller than the sample thickness. As T decreases, the network breaks into sparse filamentary paths while the Mott law changes to a different T dependence, which is derived using the percolation theory methods. In one dimension, deviations from the Mott law are known to exist at all temperatures because of rare fluctuations. The evolution of such fluctuations from highly resistive “breaks” at high T to highly conducting “shorts” at low T is elucidated. https://escholarship.org/uc/item/4dh582wv Thu, 7 May 2026 00:00:00 +0000 Rodin, AS Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/46q3n476 Understanding Mode Connectivity via Parameter Space Symmetry https://escholarship.org/uc/item/46q3n476 Thu, 7 May 2026 00:00:00 +0000 Zhao, Bo Dehmamy, Nima Walters, Robin Yu, Rose https://escholarship.org/uc/item/3v7331hp We show by a meta-analysis of the available Quantum Monte Carlo (QMC) results that two-dimensional fermions with repulsive interactions exhibit universal behavior in the strongly correlated regime, and that their freezing transition can be described using a quantum generalization of the classical Hansen-Verlet freezing criterion. We calculate the liquid-state energy and the freezing point of the 2D dipolar Fermi gas (2DDFG) using a variational method by taking ground-state wave functions of 2D electron gas (2DEG) as trial states. A comparison with the recent fixed-node diffusion Monte Carlo analysis of the 2DDFG shows that our simple variational technique captures more than of the correlation energy, and predicts the freezing transition within the uncertainty bounds of QMC. Finally, we utilize the ground-state wave functions of 2DDFG as trial states and provide a variational account of the effects of finite 2D confinement width. Our results indicate significant beyond mean-field... https://escholarship.org/uc/item/3v7331hp Thu, 7 May 2026 00:00:00 +0000 Babadi, Mehrtash Skinner, Brian Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Demler, Eugene https://escholarship.org/uc/item/3sc5129d We perform combined resistivity and compressibility studies of two-dimensional hole and electron systems which show the apparent metal-insulator transition--a crossover in the sign of deltaR/deltaT with changing density. No thermodynamic anomalies have been detected in the crossover region. Instead, despite a tenfold difference in r(s), the compressibility of both electrons and holes is well described by the theory of nonlinear screening of the random potential. We show that the resistivity exhibits a scaling behavior near the percolation threshold found from analysis of the compressibility. Notably, the percolation transition occurs at a much lower density than the crossover. https://escholarship.org/uc/item/3sc5129d Thu, 7 May 2026 00:00:00 +0000 Allison, G Galaktionov, EA Savchenko, AK Safonov, SS Fogler, MM https://orcid.org/0000-0001-8239-7221 Simmons, MY Ritchie, DA https://escholarship.org/uc/item/3s87t04x We consider variations of the low temperature chemical potential and magnetization of laterally confined two-dimensional interacting electrons in a strong magnetic field. Cases of axially symmetrical (a quantum dot) and strongly elongated (a quantum wire) spatial distributions of electron density are studied. We commonly refer to both types of systems as ‘‘islands.’’ The calculations are performed in the mean-field approximation. In this approximation the system consists of alternating regions of compressible and incompressible liquids. We are focusing on islands with typical widths b, which are much larger than the Bohr radius in a semiconductor aB, and argue that the density profile is formed mainly by electrostatic forces, has a domelike shape, and changes only slightly in the whole range of magnetic fields. We calculated numerically the chemical potential and the magnetization as functions of the magnetic field and found them to be in sharp contrast to the conventional result... https://escholarship.org/uc/item/3s87t04x Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Levin, EI Shklovskii, BI https://escholarship.org/uc/item/3s07v5c2 We explore attractive dipolar interaction in indirect excitons (IXs). For one layer of IXs in a single pair of coupled quantum wells (CQWs), the out-of-plane IX electric dipoles lead to repulsive dipolar interaction between IXs. The attractive dipolar interaction between IXs is realized in a two-CQW heterostructure with two IX layers in two separated CQW pairs. We found both in experimental measurements and theoretical simulations that increasing density of IXs in one layer causes a monotonic energy reduction for IXs in the other layer. We also found an in-plane shift of a cloud of IXs in one layer towards a cloud of IXs in the other layer. This behavior is qualitatively consistent with attractive dipolar interaction. The measured IX energy reduction and IX cloud shift are higher than the values given by the correlated liquid theory. https://escholarship.org/uc/item/3s07v5c2 Thu, 7 May 2026 00:00:00 +0000 Choksy, DJ Xu, Chao Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Norman, J Gossard, AC https://escholarship.org/uc/item/3rm819cv Natural hyperbolic materials with dielectric permittivities of opposite signs along different principal axes can confine long-wavelength electromagnetic waves down to the nanoscale, well below the diffraction limit. Confined electromagnetic waves coupled to phonons in hyperbolic dielectrics including hexagonal boron nitride (hBN) and α-MoO₃ are referred to as hyperbolic phonon polaritons (HPPs). HPP dissipation at ambient conditions is substantial, and its fundamental limits remain unexplored. Here, we exploit cryogenic nanoinfrared imaging to investigate propagating HPPs in isotopically pure hBN and naturally abundant α-MoO₃ crystals. Close to liquid-nitrogen temperatures, losses for HPPs in isotopic hBN drop significantly, resulting in propagation lengths in excess of 8 μm, with lifetimes exceeding 5 ps, thereby surpassing prior reports on such highly confined polaritonic modes. Our nanoscale, temperature-dependent imaging reveals the relevance of acoustic... https://escholarship.org/uc/item/3rm819cv Thu, 7 May 2026 00:00:00 +0000 Ni, Guangxin McLeod, Alexander S Sun, Zhiyuan Matson, Joseph R Lo, Chiu Fan Bowen Rhodes, Daniel A Ruta, Francesco L Moore, Samuel L Vitalone, Rocco A Cusco, Ramon Artús, Luis Xiong, Lin Dean, Cory R Hone, James C Millis, Andrew J Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Edgar, James H Caldwell, Joshua D Basov, DN https://escholarship.org/uc/item/3jv4m7p0 Characteristic dimensions of carbon nanoscrolls—“buckyrolls”—are calculated by analyzing the competition between elastic, van der Waals, and electrostatic energies for representative models of suspended and substrate-deposited graphene samples. The results are consistent with both atomistic simulations and experimental observations of scrolled graphene edges. Electrostatic control of the wrapping is shown to be practically feasible and its possible device applications are indicated. https://escholarship.org/uc/item/3jv4m7p0 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Neto, AH Castro Guinea, F https://escholarship.org/uc/item/3ds5p599 We study the energy spectrum of a graphene bilayer in the presence of transverse electric and magnetic fields. We find that the resulting Landau levels exhibit a nonmonotonic dependence on the electric field, as well as numerous level crossings. This behavior is explained using quasiclassical quantization rules that properly take into account the pseudospin of the quasiparticles. The pseudospin generates the Berry phase, which leads to a shift in energy quantization and results in a pseudo-Zeeman effect. The latter depends on the electric field, alternates in sign among the two valleys, and also reduces the band gap. Analytic formulas for other pseudospin-related quantities, such as the anomalous Hall conductivity, are derived and compared with prior theoretical work. https://escholarship.org/uc/item/3ds5p599 Thu, 7 May 2026 00:00:00 +0000 Zhang, Lingfeng M Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Arovas, Daniel P https://escholarship.org/uc/item/3cv1n0mv We present a controlled method for computing the exchange coupling in correlated one-dimensional electron systems based on the relation between the exchange constant and the pair-correlation function of spinless electrons. This relation is valid in several independent asymptotic regimes, including the low-electron-density case, under the general condition of a strong spin-charge separation. Explicit formulas for the exchange constant are obtained for thin quantum rings and wires with realistic Coulomb interactions by calculating the pair-correlation function via a many-body instanton approach. A remarkably smooth interpolation between high- and low-electron-density results is shown to be possible. These results are applicable to the case of one-dimensional wires of intermediate width as well. Our method can be easily generalized to other interaction laws, such as the inverse distance squared one of the Calogero-Sutherland-Moser model. We demonstrate excellent agreement with the... https://escholarship.org/uc/item/3cv1n0mv Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Pivovarov, Eugene https://escholarship.org/uc/item/3963b63s We study a two-dimensional motion of a charged particle in a weak random potential and a perpendicular magnetic field. The correlation length of the potential is assumed to be much larger than the de Broglie wavelength. Under such conditions, the motion on not too large length scales is described by classical equations of motion. We show that the phase-space averaged diffusion coefficient is given by the Drude-Lorentz formula only at magnetic fields B smaller than certain value Bc. At larger fields, the chaotic motion is suppressed and the diffusion coefficient becomes exponentially small. In addition, we calculate the quantum-mechanical localization length as a function of B at the minima of σxx. At BBc, this decrease becomes very rapid and the localization length ceases to be exponentially large at a field B*, which is only slightly larger than Bc. Implications for the crossover from the Shubnikov–de Haas oscillations to the quantum Hall effect are discussed. https://escholarship.org/uc/item/3963b63s Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Dobin, A Yu Perel, VI Shklovskii, BI https://escholarship.org/uc/item/38x5r2v7 We describe a variational procedure for calculating the energy of an electron gas in which the long-range Coulomb interaction is truncated, for example by the screening effect of a nearby metallic gate. We use this procedure to compute the quantum capacitance of a two-dimensional electron gas next to a metallic gate as a function of electron density and spin polarization. The accuracy of the method is verified against published Monte Carlo data. The results compare favorably with a recent experiment. https://escholarship.org/uc/item/38x5r2v7 Thu, 7 May 2026 00:00:00 +0000 Skinner, Brian Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/3783q5n5 The Hall conductivity σxy of a two-dimensional electron system is quantized in units of e2h when the Fermi level is located in the gap between two Landau levels. We consider the deviation of σxy from a quantized value caused by the thermal activation of electrons to the extended states for the case of a long range random potential. This deviation is of the form σxy∗exp(−ΔT). The prefactor σxy∗ is equal to e2h at temperatures above a characteristic value T2. Below T2, σxy∗ decays according to a power law: σxy∗ = e2h(TT2)γ. The generalization to fractional Hall plateaux is discussed. https://escholarship.org/uc/item/3783q5n5 Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/36r7s50v I propose an effective theory of zero-temperature phases of the quantum Hall stripes: a smectic phase where the stripes are static and a novel quantum nematic phase where the positional order is destroyed by quantum fluctuations. The nematic is viewed as a Bose condensate of dislocations whose interactions are mediated by a U(1) gauge field. Collective mode spectrum and the dynamical structure factor in the two phases are calculated. https://escholarship.org/uc/item/36r7s50v Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/32h2k9b2 We study the ground state of a clean two-dimensional electron liquid in a weak magnetic field where N≫1 lower Landau levels are completely filled and the upper level is partially filled. It is shown that the electrons at the upper Landau level form domains with filling factors equal to 1 and zero. The domains alternate with a spatial period of order of the cyclotron radius, which is much larger than the interparticle distance at the upper Landau level. The one-particle density of states, which can be probed by tunneling experiments, is shown to have a gap linearly dependent on the magnetic field in the limit of large N. https://escholarship.org/uc/item/32h2k9b2 Thu, 7 May 2026 00:00:00 +0000 Koulakov, AA Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/2xr5r9ns A variational method is proposed for calculating the percolation threshold, the real-space structure, and the ground-state energy of a disordered two-dimensional electron liquid. Its high accuracy is verified against exact asymptotics and prior numerical results. The inverse thermodynamical density of states is shown to have a strongly asymmetric minimum at a density that is approximately the triple of the percolation threshold. This implies that the experimentally observed metal-insulator transition takes place well before the percolation point is reached. https://escholarship.org/uc/item/2xr5r9ns Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/2t22d2wq Dragging of light by moving media was predicted by Fresnel1 and verified by Fizeau’s celebrated experiments2 with flowing water. This momentous discovery is among the experimental cornerstones of Einstein’s special relativity&nbsp;theory and is well understood3,4 in the context of relativistic kinematics. By contrast, experiments on dragging photons by an electron flow in solids are riddled with inconsistencies and have so far eluded agreement with the theory5–7. Here we report on the electron flow dragging surface plasmon polaritons8,9 (SPPs): hybrid quasiparticles of infrared photons and electrons in graphene. The drag is visualized directly through infrared nano-imaging of propagating plasmonic waves in the presence of a high-density current. The polaritons in graphene shorten their wavelength when propagating against the drifting carriers. Unlike the Fizeau effect for light, the SPP drag by electrical currents defies explanation by simple kinematics and is linked to the nonlinear... https://escholarship.org/uc/item/2t22d2wq Thu, 7 May 2026 00:00:00 +0000 Dong, Y Xiong, L Phinney, IY Sun, Z Jing, R McLeod, AS Zhang, S Liu, S Ruta, FL Gao, H Dong, Z Pan, R Edgar, JH Jarillo-Herrero, P Levitov, LS Millis, AJ Fogler, MM https://orcid.org/0000-0001-8239-7221 Bandurin, DA Basov, DN https://escholarship.org/uc/item/2sk903d8 Plasmons are directly launched in graphene, and their key parameters — propagation and attenuation — are studied with near-field infrared nano-imaging. https://escholarship.org/uc/item/2sk903d8 Thu, 7 May 2026 00:00:00 +0000 Fei, Z Rodin, AS Andreev, GO Bao, W McLeod, AS Wagner, M Zhang, LM Zhao, Z Thiemens, M Dominguez, G Fogler, MM https://orcid.org/0000-0001-8239-7221 Neto, AH Castro Lau, CN Keilmann, F Basov, DN https://escholarship.org/uc/item/2nb3g2g9 Charge density waves are thought to be common in two-dimensional electron systems in quantizing magnetic fields. Such phases are formed by the quasiparticles of the topmost occupied Landau level when it is partially filled. One class of charge density wave phases can be described as electron solids. In weak magnetic fields (at high Landau levels) solids with many particles per unit cell—bubble phases—predominate. In strong magnetic fields (at the lowest Landau level) only crystals with one particle per unit cell—Wigner crystals—can form. Experimental identification of these phases is facilitated by the fact that even a weak disorder influences their DC and AC magnetotransport in a very specific way. In the AC domain, a range of frequencies appears where the electromagnetic response is dominated by magnetophonon collective modes. The effect of disorder is to localize the collective modes and to create an inhomogeneously broadened absorption line, the pinning mode. In recent microwave... https://escholarship.org/uc/item/2nb3g2g9 Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/2bm1q3kp We report on a method for the realization of two-dimensional electrostatic lattices for excitons using patterned interdigitated electrodes. Lattice structure is set by the electrode pattern and depth of the lattice potential is controlled by applied voltages. We demonstrate square, hexagonal, and honeycomb lattices created by this method. https://escholarship.org/uc/item/2bm1q3kp Thu, 7 May 2026 00:00:00 +0000 Remeika, M Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Hanson, M Gossard, AC https://escholarship.org/uc/item/1zx5q7zg We theoretically study the low-energy electromagnetic response of Bardeen-Cooper-Schrieffer–type superconductors focusing on propagating collective modes that are observable with terahertz near-field optics. The interesting frequency and momentum range is ω&lt;2Δ and q&lt;1/ξ, where Δ is the gap and ξ is the coherence length. We show that it is possible to observe the superfluid plasmons, amplitude (Higgs) modes, Bardasis-Schrieffer modes, and Carlson-Goldman modes using the terahertz near-field technique, although none of these modes couple linearly to far-field radiation. Coupling of terahertz near-field radiation to the amplitude mode requires particle-hole symmetry breaking, while coupling to the Bardasis-Schrieffer mode does not and is typically stronger. For parameters appropriate to layered superconductors of current interest, the Carlson-Goldman mode appears in the near-field reflection coefficient as a weak feature in the subterahertz frequency range. In a system of two... https://escholarship.org/uc/item/1zx5q7zg Thu, 7 May 2026 00:00:00 +0000 Sun, Zhiyuan Fogler, MM https://orcid.org/0000-0001-8239-7221 Basov, DN Millis, Andrew J https://escholarship.org/uc/item/1wg8s52b We study transport of indirect excitons in GaAs/AlGaAs coupled quantum wells in linear lattices created by laterally modulated gate voltage. The localization-delocalization transition for transport across the lattice was observed with reducing lattice amplitude or increasing exciton density. The exciton interaction energy at the transition is close to the lattice amplitude. These results are consistent with the model, which attributes the localization-delocalization transition to the interaction-induced percolation of the exciton gas through the external potential. We also discuss applications of the lattice potentials for estimating the strength of disorder and exciton interaction. https://escholarship.org/uc/item/1wg8s52b Thu, 7 May 2026 00:00:00 +0000 Remeika, M Graves, JC Hammack, AT Meyertholen, AD Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Hanson, M Gossard, AC https://escholarship.org/uc/item/1kr865n9 Disequilibrium is a highly prevalent age-related condition that increases fall risk, yet the genetic architecture underlying vestibular function remains poorly defined. Here, we performed genome-wide association studies (GWAS) of vestibular-evoked potentials (VsEP) and raised-beam performance across young and aged Hybrid Mouse Diversity Panel (HMDP) strains. In young mice, we identified genome-wide significant loci on chromosomes 4, 7, 14, and 15, along with suggestive associations on chromosomes 6 and 14. To refine candidate genes, we integrated cochlear and cerebellar cis-eQTL data from BXD strains with human cochlear transcriptomic profiles, revealing 12 cochlea-enriched genes within linkage disequilibrium intervals. Single-cell RNA sequencing localized Agbl4, Cntnap2, Dmc1, and Pcdh20 to vestibular hair cells, and Gpnmb to melanocytes of the inner ear. These findings highlight coordinated contributions of sensory and non-sensory cell types to vestibular performance. Although... https://escholarship.org/uc/item/1kr865n9 Thu, 7 May 2026 00:00:00 +0000 Ninoyu, Yuzuru Pan, Calvin Luu, Jennifer Rashid, Sameeha Johnston, Jadyn Ortega, Briana Boussaty, Ely Lu, Lu Clifford, Royce https://orcid.org/0000-0002-5515-4336 Mohammadi, Pejman Telese, Francesca Palmer, Abraham A Lusis, Aldons J Friedman, Rick A https://orcid.org/0000-0002-5490-8562 https://escholarship.org/uc/item/1gv169r0 The first-order interaction correction to the irreducible polarization function of pristine graphene is studied at arbitrary relation between momentum and frequency. The results are used to calculate the dielectric function and the dynamical conductivity of graphene beyond the standard random-phase approximation. The computed static dielectric constant compares favorably with recent experiments. https://escholarship.org/uc/item/1gv169r0 Thu, 7 May 2026 00:00:00 +0000 Sodemann, I Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/1cb1w7k0 Collective electronic modes or lattice vibrations usually prohibit propagation of electromagnetic radiation through the bulk of common materials over a frequency range associated with these oscillations. However, this textbook tenet does not necessarily apply to layered crystals. Highly anisotropic materials often display nonintuitive optical properties and can permit propagation of subdiffractional waveguide modes, with hyperbolic dispersion, throughout their bulk. Here, we report on the observation of optically induced electronic hyperbolicity in the layered transition metal dichalcogenide tungsten diselenide (WSe₂). We used photoexcitation to inject electron-hole pairs in WSe₂ and then visualized, by transient nanoimaging, the hyperbolic rays that traveled along conical trajectories inside of the crystal. We establish here the signatures of programmable hyperbolic electrodynamics and assess the role of quantum transitions of excitons within the Rydberg... https://escholarship.org/uc/item/1cb1w7k0 Thu, 7 May 2026 00:00:00 +0000 Sternbach, AJ Chae, SH Latini, S Rikhter, AA Shao, Y Li, B Rhodes, D Kim, B Schuck, PJ Xu, X Zhu, X-Y Averitt, RD Hone, J Fogler, MM https://orcid.org/0000-0001-8239-7221 Rubio, A Basov, DN https://escholarship.org/uc/item/1bq5v6dx The legend of Democritus the laughing philosopher, alone or in juxtaposition with his counterpart Heraclitus the weeping philosopher, first appears as an anecdote (chreia) in Imperial age philosophers and poets, but has gone on to influence literature and visual arts down to the present day. An examination of its sources reveals interesting discussions of a frustrating mess of emotions: laughing and weeping, anger and tranquility. Melancholy is not an emotion but a disease or character disposition, one which is the apparent cause of all of these symptoms of manic depression (to speak anachronistically). In this chapter, I discuss the ancient influences on the anecdote coming from the writings of Heraclitus of Ephesus (flourished circa 500 BCE), Democritus of Abdera (born circa 460 BCE), and from a classical account of melancholy attributed to Aristotle. https://escholarship.org/uc/item/1bq5v6dx Thu, 7 May 2026 00:00:00 +0000 Johnson, Monte Ransome https://escholarship.org/uc/item/18s183g8 We analyze electrostatic interaction between a sharp conducting tip and a thin one-dimensional wire, e.g., a carbon nanotube, in a scanned gate microscopy (SGM) experiment. The problem is analytically tractable if the wire resides on a thin dielectric substrate above a metallic backgate. The characteristic spatial scale of the electrostatic coupling to the tip is equal to its height above the substrate. Numerical simulations indicate that imaging of individual electrons by SGM is possible once the mean electron separation exceeds this scale (typically, a few tens of nm). Differences between weakly and strongly invasive SGM regimes are pointed out. https://escholarship.org/uc/item/18s183g8 Thu, 7 May 2026 00:00:00 +0000 Zhang, Lingfeng M Fogler, Michael M https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/1503b8qw Collective modes in multilayer graphene, such as plasmons and phonons, exhibit sensitivity to displacement fields and interlayer coupling, distinguishing them from their counterparts in single-layer graphene. Here, we engineer collective modes in charge-transfer heterostructures composed of multilayer graphene and . In heterostructures with a single interface, the charge transfer generates displacement fields up to 7&nbsp;V/nm at the interface between and the adjacent graphene layer—the highest value achieved through charge-transfer methods. As a result of the broken inversion symmetry, we discover enhanced nonlinear optical response and modified phonon selection rules. Conversely, we find that multilayer graphene sandwiched between two flakes causes displacement fields to cancel. There, we achieve carrier densities as high as in multilayer graphene and restore the phonon selection rules to their unperturbed state. Meanwhile, we demonstrate that plasmonic properties derive... https://escholarship.org/uc/item/1503b8qw Thu, 7 May 2026 00:00:00 +0000 Moore, Samuel L Sánchez, Miguel Sánchez Strasbourg, MC Shao, Y Pack, J Wang, Y Rizzo, DJ Jessen, BS Cothrine, Matthew Mandrus, David G Taniguchi, Takashi Watanabe, Kenji Burch, KS Dean, CR Hone, J Fogler, M https://orcid.org/0000-0001-8239-7221 Millis, AJ Rubio, A Schuck, PJ Stauber, T Basov, DN https://escholarship.org/uc/item/1438531k It is known experimentally that at not very large filling factors ν the quantum Hall conductivity peaks corresponding to the same Landau level number N and two different spin orientations are well separated. These peaks occur at half-integer filling factors ν=2N+1/2 and ν=2N+3/2 so that the distance δν between them is unity. As ν increases δν shrinks. Near certain N=Nc two peaks merge into a single peak at ν=2N+1. We argue that this collapse of the spin splitting at low magnetic fields is attributed to the disorder-induced destruction of the exchange enhancement of the electron g factor. We use the mean-field approach to show that in the limit of zero Zeeman energy δν experiences a second-order phase transition as a function of the magnetic field. We give explicit expressions for Nc in terms of a sample’s parameters. For example, we predict that for high-mobility heterostructures Nc=0.9dn5/6ni-1/3, where d is the spacer width, n is the density of the two-dimensional electron gas,... https://escholarship.org/uc/item/1438531k Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Shklovskii, BI https://escholarship.org/uc/item/13w0k2rr We report on the principle and realization of a new trap for excitons--the diamond electrostatic trap--which uses a single electrode to create a confining potential for excitons. We also create elevated diamond traps which permit evaporative cooling of the exciton gas. We observe the collection of excitons towards the trap center with increasing exciton density. This effect is due to screening of disorder in the trap by the excitons. As a result, the diamond trap behaves as a smooth parabolic potential which realizes a cold and dense exciton gas at the trap center. https://escholarship.org/uc/item/13w0k2rr Thu, 7 May 2026 00:00:00 +0000 High, AA Thomas, AK Grosso, G Remeika, M Hammack, AT Meyertholen, AD Fogler, MM https://orcid.org/0000-0001-8239-7221 Butov, LV Hanson, M Gossard, AC https://escholarship.org/uc/item/13m5c84s The binding energy and wave functions of two-dimensional indirect biexcitons are studied analytically and numerically. It is proven that stable biexcitons exist only when the distance between electron and hole layers is smaller than a certain critical threshold. Numerical results for the biexciton binding energies are obtained using the stochastic variational method and compared with the analytical asymptotics. The threshold interlayer separation and its uncertainty are estimated. The results are compared with those obtained by other techniques, in particular, the diffusion Monte Carlo method and the Born-Oppenheimer approximation. https://escholarship.org/uc/item/13m5c84s Thu, 7 May 2026 00:00:00 +0000 Meyertholen, AD Fogler, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/135022td We reexamine a long-standing problem of the finite-frequency conductivity of a weakly pinned two-dimensional classical Wigner crystal. In this system an inhomogeneously broadened absorption line (pinning mode) centered at disorder- and magnetic-field-dependent frequency ωp is known to appear. We show that the relative linewidth Δωp/ωp of the pinning mode is of the order of 1 in weak magnetic fields, exhibits a power-law decrease in intermediate fields, and eventually saturates at a small value in strong magnetic fields. The linewidth narrowing is due to a peculiar mechanism of mixing between the stiffer longitudinal and the softer transverse components of the collective excitations. The width of the high-field resonance proves to be related to the density of states in the low-frequency tail of the zero-field phonon spectrum. We find a qualitative agreement with recent experiments and point out differences from the previous theoretical work on the subject. https://escholarship.org/uc/item/135022td Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Huse, David A https://escholarship.org/uc/item/0z93601s Abstract We introduce RGFlow, a deep neural network–based real-space renormalization group (RG) framework tailored for continuum scalar field theories. Leveraging generative capabilities of flow-based neural networks, RGFlow autonomously learns real-space RG transformations from data without prior knowledge of the underlying model. In contrast to conventional approaches, RGFlow is bijective (information-preserving) and is optimized based on the principle of minimal mutual information. We demonstrate the method on two examples. The first one is a one-dimensional Gaussian model, where RGFlow is shown to learn the classical decimation rule. The second is the two-dimensional ϕ4 theory, where the network successfully identifies a Wilson–Fisher-like critical point and provides an estimate of the correlation-length critical exponent. https://escholarship.org/uc/item/0z93601s Thu, 7 May 2026 00:00:00 +0000 Zhao, Yueqi Fogler, Michael https://orcid.org/0000-0001-8239-7221 You, Yi-Zhuang https://orcid.org/0000-0003-4080-5340 https://escholarship.org/uc/item/0xk3n77b A Comment on the Letter by Alexander O. Gogolin, Phys. Rev. Lett. 84, 1760 (2000). https://escholarship.org/uc/item/0xk3n77b Thu, 7 May 2026 00:00:00 +0000 Fogler, Michael M https://orcid.org/0000-0001-8239-7221 Wang, Ziqiang https://escholarship.org/uc/item/0hs5h14q We investigate theoretically the effect of a finite electric field on the resistivity of a disordered one-dimensional system in the variable-range hopping regime. We find that at low fields the transport is inhibited by rare fluctuations in the random distribution of localized states that create high-resistance breaks in the hopping network. As the field increases, the breaks become less resistive. In strong fields the breaks are overrun and the electron distribution function is driven far from equilibrium. The logarithm of the resistance initially shows a simple exponential drop with the field, followed by a logarithmic dependence, and finally, by an inverse square-root law. https://escholarship.org/uc/item/0hs5h14q Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Kelley, RS https://escholarship.org/uc/item/0fw548kq Infrared Pump-Probe Spectroscopy of Plasmons in Graphene and Semiconductors https://escholarship.org/uc/item/0fw548kq Thu, 7 May 2026 00:00:00 +0000 Wagner, M Fei, Z McLeod, AS Maddox, SJ Rodin, AS Bao, W Iwinski, EG Zhao, Z Goldflam, M Liu, M Dominguez, G Thiemens, M Fogler, MM https://orcid.org/0000-0001-8239-7221 Castro-Neto, AH Lau, CN Amarie, S Keilmann, F Bank, SR Averitt, RD Basov, DN https://escholarship.org/uc/item/0fw4402c We study the effect of impurities on the ground state and the low-temperature Ohmic dc transport in a one-dimensional chain and quasi-one-dimensional systems of many parallel chains. We assume that strong interactions impose a short-range periodicity of the electron positions. The long-range order of such an electron crystal (or equivalently, a 4kF charge-density wave) is destroyed by impurities, which act as strong pinning centers. We show that a three-dimensional array of chains behaves differently at large and at small impurity concentrations N. At large N, impurities divide the chains into metallic rods. Additions or removal of electrons from such rods correspond to charge excitations whose density of states exhibits a quadratic Coulomb gap. At low temperatures the conductivity is due to the variable-range hopping of electrons between the rods. It obeys the Efros-Shklovskii (ES) law, -ln σ∼(TES/T)1/2. TES decreases as N decreases, which leads to an exponential growth of σ.... https://escholarship.org/uc/item/0fw4402c Thu, 7 May 2026 00:00:00 +0000 Fogler, MM https://orcid.org/0000-0001-8239-7221 Teber, S Shklovskii, BI https://escholarship.org/uc/item/0ff7c81q The stripe phase of a two-dimensional electron system in a weak magnetic field bears a close analogy to liquid crystals. However, reduced dimensionality and unusual dynamics give rise to important differences. At finite temperature they cause divergent fluctuations and nonperturbative renormalization of hydrodynamic parameters. Such effects can be verified in microwave experiments. At low temperatures the physics is dominated by quantum fluctuations. When they are large, the transition to a novel quantum nematic phase may occur, driven by quantum proliferation of dislocations. It will be signaled by an additional low-frequency resonance in the microwave response. https://escholarship.org/uc/item/0ff7c81q Thu, 7 May 2026 00:00:00 +0000 FOGLER, MM https://orcid.org/0000-0001-8239-7221 https://escholarship.org/uc/item/09w8h7fn We analyze the results of scanning near-field infrared spectroscopy performed on thin films of a-SiO2 on Si substrate. The measured near-field signal exhibits surface-phonon resonances whose strength has a prominent thickness dependence in the range from 2 to 300nm. These observations are compared with calculations in which the tip of the near-field infrared spectrometer is modeled either as a point dipole or an elongated spheroid. The latter model accounts for the antenna effect of the tip and gives a better agreement with the experiment. Possible applications of the near-field technique for depth profiling of layered nanostructures are discussed. https://escholarship.org/uc/item/09w8h7fn Thu, 7 May 2026 00:00:00 +0000 Zhang, LM Andreev, GO Fei, Z McLeod, AS Dominguez, G Thiemens, M Castro-Neto, AH Basov, DN Fogler, MM https://orcid.org/0000-0001-8239-7221