A5091474850- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Digital Transformation in Industry
- Force Microscopy Techniques and Applications
- High-pressure geophysics and materials
- Rare-earth and actinide compounds
- Theoretical and Computational Physics
- Nonlinear Dynamics and Pattern Formation
- Organic and Molecular Conductors Research
- Quantum and electron transport phenomena
- Surface and Thin Film Phenomena
- Solid-state spectroscopy and crystallography
- Nonlinear Photonic Systems
- Liquid Crystal Research Advancements
- Characterization and Applications of Magnetic Nanoparticles
- Gene expression and cancer classification
- Adversarial Robustness in Machine Learning
- Statistical Methods in Clinical Trials
- Superconductivity in MgB2 and Alloys
- Risk and Safety Analysis
- Black Holes and Theoretical Physics
- Geophysics and Sensor Technology
- Cold Atom Physics and Bose-Einstein Condensates
- Spectral Theory in Mathematical Physics
Adobe Systems (United States)
2020-2023
Stanford University
2013-2017
SLAC National Accelerator Laboratory
2015-2017
The existence of charge density wave (CDW) correlations in cuprate superconductors has now been established. However, the nature ground state order remained uncertain because disorder and presence superconductivity typically limit CDW correlation lengths to a dozen unit cells or less. Here we explore YBa2Cu3Ox (YBCO) ortho-II ortho-VIII crystals, which belong cleanest available family, at magnetic fields excess resistive upper critical field (Hc2) where is heavily suppressed. We find an...
For materials that harbour a continuous phase transition, the susceptibility of material to various fields can be used understand nature fluctuating order and hence ordered state. Here we use anisotropic biaxial strain probe nematic URu2Si2, heavy fermion for which low temperature 'hidden order' state has defied comprehensive understanding over 30 years. Our measurements reveal component, confirming reports twofold anisotropy in broken symmetry strongly constraining theoretical models...
Nematic order has manifested itself in a variety of materials the cuprate family. We propose an effective field theory layered system with incommensurate, intertwined spin- and charge-density wave (SDW CDW) orders, each which consists two components related by ${C}_{4}$ rotations. Using variational method (which is exact large-$N$ limit), we study development nematicity from partially melting those density waves either increasing temperature or adding quenched disorder. As decreases first...
Significance Many interesting materials, including various high-temperature superconductors, exhibit a low-temperature “electron nematic” phase in which the electronic properties spontaneously break rotational symmetry of crystal. A nematic quantum critical point (QCP) marks zero-temperature transition from ground state to symmetric as function macroscopic nonthermal parameter. Here, we examine appropriate general means tune Ising systems QCP and particular show that shear strain is powerful...
Enterprise AI Assistants are increasingly deployed in domains where accuracy is paramount, making each erroneous output a potentially significant incident. This paper presents comprehensive framework for monitoring, benchmarking, and continuously improving such complex, multi-component systems under active development by multiple teams. Our approach encompasses three key elements: (1) hierarchical ``severity'' incident detection that identifies categorizes errors while attributing...
Motivated by recent observations of charge order in the pseudogap regime hole-doped cuprates, we show that crisscrossed stripe can be stabilized coherent, momentum-dependent interlayer tunneling, which is known to present several cuprate materials. We further describe how subtle variations couplings between layers lead a variety ordering arrangements, and discuss implications our results for experiments underdoped cuprates.
The elastoresistivity tensor $m_{ij,kl}$ characterizes changes in a material's resistivity due to strain. As fourth-rank tensor, can be uniquely useful probe of the symmetries and character electronic state solid. We present symmetry analysis (both presence absence magnetic field) based on crystalline point group, focusing for pedagogic purposes $D_{4h}$ group (of relevance several materials current interest). also discuss relation between various thermodynamic susceptibilities, particularly...
The high-field Hall number directly measures the carrier density in metals with closed Fermi surfaces. However, no general theorem is known to govern behavior of systems open surfaces or critical across a Lifshitz transition from topology. Using Boltzmann transport theory, authors derive analytic expressions for through such transition, and recent experiments on hole doped cuprate superconductors that suggest sudden drop below optimal doping are shown be consistent nematicity-induced transition.
Because a material with an incommensurate charge density wave (ICDW) is only quasi-periodic, Bloch's theorem does not apply and there no sharply defined Fermi surface. We will show that, as consequence, are quantum oscillations which truly periodic functions of $1/B$ (where $ B$ the magnitude applied magnetic field). For weak ICDW, exist broad ranges in approximately variations occur, but frequencies that vary inexorably unending cascade increasing $1/B$. strong e.g. quasi-crystal, survive...
Using an exact numerical solution and semiclassical analysis, we investigate quantum oscillations (QOs) in a model of bilayer system with anisotropic (elliptical) electron pocket each plane. Key features QO experiments the high temperature superconducting cuprate YBCO can be reproduced by such model, particular pattern oscillation frequencies (which reflect "magnetic breakdown" between two pockets) polar azimuthal angular dependence amplitudes. However, requisite magnetic breakdown is...
A/B tests are the gold standard for evaluating digital experiences on web. However, traditional "fixed-horizon" statistical methods often incompatible with needs of modern industry practitioners as they do not permit continuous monitoring experiments. Frequent evaluation fixed-horizon ("peeking") leads to inflated type-I error and can result in erroneous conclusions. We have released an experimentation service Adobe Experience Platform based anytime-valid confidence sequences, allowing test...
Hexagonal lattice systems (e.g., triangular, honeycomb, kagome) possess a multidimensional irreducible representation corresponding to ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and ${d}_{xy}$ symmetry. Consequently, various unconventional phases that combine these $d$-wave representations can occur, in so doing may break time-reversal spin-rotation symmetries. We show hexagonal with extended repulsive interactions exhibit instabilities the particle-hole channel either...
Harper's equation (aka the "almost Mathieu" equation) famously describes quantum dynamics of an electron on a one dimensional lattice in presence incommensurate potential with magnitude $V$ and wave number $Q$. It has been proven that all states are delocalized if is less than critical value $V_c=2t$ localized $V> V_c$. Here, we show this result (while correct) highly misleading, at least small $Q$ limit. In particular, for $VE_c$, form set narrow bands exponentially bandwidths $ \sim t\...
We propose the possible detection of broken mirror symmetries in correlated two-dimensional materials by elastotransport measurements. Using linear response theory we calculate shearconductivity $\Gamma_{xx,xy}$, defined as change longitudinal conductivity $\sigma_{xx}$ due to a shear strain $\epsilon_{xy}$. This quantity can only be non-vanishing when in-plane are and discuss how candidate states cuprate pseudogap regime (e.g. various loop current or charge orders) may exhibit finite...
The development of conversational AI assistants is an iterative process with multiple components. As such, the evaluation and continual improvement these a complex multifaceted problem. This paper introduces challenges in evaluating improving generative assistant for enterprises, which under active development, how we address challenges. We also share preliminary results discuss lessons learned.