A5056107519- Quantum many-body systems
- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Theoretical and Computational Physics
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum, superfluid, helium dynamics
- Quantum chaos and dynamical systems
- Advanced Thermodynamics and Statistical Mechanics
- Opinion Dynamics and Social Influence
- Topological Materials and Phenomena
- Spectroscopy and Quantum Chemical Studies
- Quantum optics and atomic interactions
- Neural Networks and Reservoir Computing
- Model Reduction and Neural Networks
- Atomic and Subatomic Physics Research
- Strong Light-Matter Interactions
- Quantum Mechanics and Applications
- Photonic and Optical Devices
- Graphene research and applications
- Quasicrystal Structures and Properties
- Nonlinear Dynamics and Pattern Formation
- Statistical Mechanics and Entropy
- Mechanical and Optical Resonators
Princeton University
2022-2025
Pennsylvania State University
2021-2024
University of Massachusetts Amherst
2023
College of Staten Island
2015-2022
The Graduate Center, CUNY
2017-2022
The Ohio State University
2021
City University of New York
2019-2020
Center for Theoretical Physics
2020
University of Oxford
2020
California Institute of Technology
2015-2019
We explore the high-temperature dynamics of disordered, one-dimensional XXZ model near many-body localization (MBL) transition, focusing on delocalized (i.e., "metallic") phase. In vicinity we find that this phase has following properties: (i) local magnetization fluctuations relax subdiffusively; (ii) ac conductivity vanishes zero frequency as a power law; and (iii) distribution resistivities becomes increasingly broad at low frequencies, approaching law in zero-frequency limit. argue these...
We numerically study the measurement-driven quantum phase transition of Haar-random circuits in $1+1$ dimensions. By analyzing tripartite mutual information we are able to make a precise estimate critical measurement rate $p_c = 0.17(1)$. extract estimates for associated bulk exponents that consistent with values percolation, as well those stabilizer circuits, but differ from previous case. Our surface order parameter exponent appear different or unable definitively rule out scenario where...
We address the hydrodynamics of operator spreading in interacting integrable lattice models. In these models, operators spread through ballistic propagation quasiparticles, with an front whose velocity is locally set by fastest quasiparticle velocity. systems, this depends on density other so equilibrium fluctuations cause to follow a biased random walk, and therefore broaden diffusively. Ballistic diffusive broadening are also generically present non-integrable systems one dimension; thus,...
In a many-body localized (MBL) quantum system, the ergodic hypothesis breaks down completely, giving rise to fundamentally new phase. Whether and under which conditions MBL can occur in higher dimensions remains an outstanding challenge both for experiments theory. Here, we experimentally explore relaxation dynamics of interacting gas fermionic potassium atoms loaded two-dimensional optical lattice with different quasi-periodic potentials along two directions. We observe dramatic slowing...
Unitary circuits subject to repeated projective measurements can undergo an entanglement phase transition (EPT) as a function of the measurement rate. This is generally understood in terms competition between scrambling effects unitary dynamics and disentangling measurements. We find that, surprisingly, EPTs are possible even absence dynamics, where they best arising from alone. finding motivates us introduce measurement-only models, which "scrambling" "unscrambling" driving EPT...
Systems of strongly interacting dipoles offer an attractive platform to study many-body localized phases, owing their long coherence times and strong interactions. We explore conditions under which such phases persist in the presence power-law interactions supplement our analytic treatment with numerical evidence states one dimension. propose analyze several experimental systems that can be used observe probe states, including ultracold polar molecules solid-state magnetic spin impurities.
The low‐frequency response of systems near the many‐body localization phase transition, on either side is dominated by contributions from rare regions that are locally “in other phase”, i.e., localized in a system typically thermal, or thermal localized. Rare affect properties phase, especially one dimension, acting as bottlenecks for transport and growth entanglement, whereas act local “baths” dominate MBL phase. We review recent progress understanding these rare‐region effects, discuss...
We address the nature of spin transport in integrable XXZ chain, focusing on isotropic Heisenberg limit. calculate diffusion constant using a kinetic picture based generalized hydrodynamics combined with Gaussian fluctuations: we find that it diverges, and show self-consistent treatment this divergence gives superdiffusion, an effective time-dependent scales as D(t)∼t^{1/3}. This exponent had previously been observed large-scale numerical simulations, but not theoretically explained. briefly...
We argue that the ac conductivity $\ensuremath{\sigma}(\ensuremath{\omega})$ in many-body localized phase is a power law of frequency $\ensuremath{\omega}$ at low frequency: specifically, $\ensuremath{\sigma}(\ensuremath{\omega})\ensuremath{\sim}{\ensuremath{\omega}}^{\ensuremath{\alpha}}$ with exponent $\ensuremath{\alpha}$ approaching 1 transition to thermal phase, and asymptoting 2 deep phase. identify two separate mechanisms giving rise this law: dominated by rare resonant pairs...
The Kardar-Parisi-Zhang (KPZ) universality class describes the coarse-grained behavior of a wealth classical stochastic models. Surprisingly, KPZ was recently conjectured to also describe spin transport in one-dimensional quantum Heisenberg model. We tested this conjecture by experimentally probing cold-atom simulator via relaxation domain walls chains up 50 spins. found that domain-wall is indeed governed dynamical exponent z = 3/2 and occurrence scaling requires both integrability...
We introduce an approach to compute reduced density matrices for local quantum unitary circuits of finite depth and infinite width. Suppose the time-evolved state under circuit is a matrix-product with bond dimension $D$; then matrix half-infinite system has same spectrum as appropriate $D\times D$ acting on ancilla space. show that at different spatial cuts are related by channels This channel allows efficient numerical evaluation entanglement R\'enyi entropies their fluctuations times in...
This review summarizes recent advances in our understanding of anomalous transport spin chains, viewed through the lens integrability. Numerical advances, based on tensor-network methods, have shown that many canonical integrable chains—most famously Heisenberg model—is anomalous. Concurrently, framework generalized hydrodynamics has been extended to explain some mechanisms underlying transport. We present what is currently understood about these mechanisms, and discuss how they resemble...
A quantum system subject to continuous measurement and postselection evolves according a non-Hermitian Hamiltonian. We show that, as one increases the strength of postselection, this Hamiltonian can undergo spectral phase transition. On side transition (for weak postselection), an initially mixed density matrix remains at all times, unentangled state develops volume-law entanglement; on other side, arbitrary initial approaches unique pure with low entanglement. identify exceptional point in...
Repeated local measurements of quantum many-body systems can induce a phase transition in their entanglement structure. These measurement-induced transitions (MIPTs) have been studied for various types dynamics, yet most cases yield quantitatively similar critical exponents, making it unclear how many distinct universality classes are present. Here, we probe the properties conformal field theories governing these MIPTs using numerical transfer-matrix method, which allows us to extract...
Monitored quantum circuits can exhibit an entanglement transition as a function of the rate measurements, stemming from competition between scrambling unitary dynamics and disentangling projective measurements. We study how in nonunitary be enriched presence charge conservation, using combination exact numerics mapping onto statistical mechanics model constrained hard-core random walkers. uncover charge-sharpening that separates different phases with volume-law scaling entanglement,...
The authors provide an analytic theory of the transport magnetization in a set interacting anisotropic spin chains. Even though these are many-body systems with diffusive on average, full distribution that gives rise to average is far from Gaussian -- fluctuations that, unlike conventional diffusion, comparable mean. This example how same hydrodynamics can belong distinct dynamical universality classes.
Nascent quantum computers motivate the exploration of many-body systems in nontraditional scenarios. For example, it has become natural to explore dynamics evolving under both unitary evolution and measurement. Such can undergo dynamical phase transitions entanglement properties trajectories conditional on measurement outcomes. Here, we which one attempts (locally) use those outcomes steer system toward a target state, study resulting diagram as function feedback rates. Steering succeeds...
Abstract A fundamental principle of chaotic quantum dynamics is that local subsystems eventually approach a thermal equilibrium state. The corresponding timescales increase with subsystem size as equilibration limited by the hydrodynamic build-up fluctuations on extended length scales. We perform large-scale simulations monitor particle-number in tunable ladders hard-core bosons and explore how changes system crosses over from integrable to fully dynamics. Our results indicate growth...
We present a family of local quantum channels whose steady states exhibit stable mixed-state symmetry-protected topological (SPT) order. Motivated by recent experimental progress on "erasure conversion" techniques that allow one to identify (herald) decoherence processes, we consider open systems with biased erasure noise, which leads strongly symmetric heralded errors. utilize this heralding construct correction protocol effectively confines errors into short-ranged pairs in the state....
The lifetime of superconducting qubits is limited by dielectric loss, and a major source loss the native oxide present at surface metal. Specifically, tantalum-based have been demonstrated with record lifetimes, but presence two-level systems in tantalum oxide. Here, we demonstrate strategy for avoiding formation encapsulating noble metals that do not form By depositing few nanometers Au or AuPd alloy before breaking vacuum, completely suppress formation. Microwave measurements resonators...
We consider strongly interacting systems of effective spins, subject to dissipative spin-flip processes associated with optical pumping. predict the existence novel magnetic phases in steady state this system, which emerge due competition between coherent and processes. Specifically, for anisotropic spin-spin interactions, we find ferromagnetic, antiferromagnetic, spin-density-wave, staggered-$XY$ states, are separated by nonequilibrium phase transitions meeting at a Lifshitz point. These...
We show that the effective spin-spin interaction between three-level atoms confined in a multimode optical cavity is long-ranged and sign-changing, like RKKY interaction; therefore, ensembles of such subject to frozen-in positional randomness can realize spin systems having disordered frustrated interactions. argue that, whenever couple sufficiently many modes, cavity-mediated interactions give rise glass. In addition, we quantum dynamics cavity-confined Bose-Hubbard model with strongly...
We study many-body-localized (MBL) systems that are weakly coupled to thermalizing environments, focusing on the spectral functions of local operators. These carry signatures localization even away from limit perfectly isolated systems. find that, in vanishing coupling a bath, MBL come two varieties, with either discrete or continuous spectra. Both varieties exhibit ``soft gap'' at zero frequency spatially averaged operators, which serves as diagnostic for localization. estimate degree bath...