A5016312433- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum many-body systems
- Quantum Mechanics and Applications
- Quantum-Dot Cellular Automata
- Physics of Superconductivity and Magnetism
- Advanced Thermodynamics and Statistical Mechanics
- Quantum and electron transport phenomena
- Theoretical and Computational Physics
- Cryptography and Data Security
- Neural Networks and Reservoir Computing
- Tensor decomposition and applications
- nanoparticles nucleation surface interactions
- Cold Atom Physics and Bose-Einstein Condensates
- Complexity and Algorithms in Graphs
- Strong Light-Matter Interactions
- Quantum chaos and dynamical systems
- Blockchain Technology Applications and Security
- Computability, Logic, AI Algorithms
- Physical Unclonable Functions (PUFs) and Hardware Security
University of California, Berkeley
2019-2023
Lawrence Berkeley National Laboratory
2021-2023
Many-body chaos has emerged as a powerful framework for understanding thermalization in strongly interacting quantum systems. While recent analytic advances have sharpened our intuition many-body certain large N theories, it proven challenging to develop precise numerical tools capable of exploring this phenomenon generic Hamiltonians. To end, we utilize massively parallel, matrix-free Krylov subspace methods calculate dynamical correlators the Sachdev-Ye-Kitaev model up N=60 Majorana...
The existence of prethermal phases matter in long-range interacting systems is remarkably robust, opening the door to experimental realization a novel, disorder-free, discrete time crystal 1D.
We analyze the dynamics of periodically-driven (Floquet) Hamiltonians with short- and long-range interactions, finding clear evidence for a thermalization time, $\tau^*$, that increases exponentially drive frequency. observe this behavior, both in systems short-ranged where our results are consistent rigorous bounds, such bounds do not exist at present. Using combination heating entanglement dynamics, we explicitly extract effective energy scale controlling rate thermalization. Finally,...
We propose and analyze a novel interactive protocol for demonstrating quantum computational advantage, which is efficiently classically verifiable. Our relies upon the cryptographic hardness of trapdoor claw-free functions (TCFs). Through surprising connection to Bell's inequality, our avoids need an adaptive hardcore bit, with essentially no increase in circuit complexity extra assumptions. Crucially, this expands set compatible TCFs, we two new constructions: one based decisional...
Recently, quantum computing experiments have for the first time exceeded capability of classical computers to perform certain computations – a milestone termed "quantum computational advantage." However, verifying output device in these required extremely large computations. An exciting next step demonstrating would be implement tests advantage with efficient verification, such that larger system sizes can tested and verified. One proposals an efficiently-verifiable test quantumness consists...
The multiplication of superpositions numbers is a core operation in many quantum algorithms. standard method for (both classical and quantum) has runtime quadratic the size inputs. Quantum circuits with asymptotically fewer gates have been developed, but generally exhibit large overheads, especially number ancilla qubits. In this work, we introduce new paradigm sub-quadratic-time zero qubits -- only involved are input output registers themselves. Our algorithm achieves an asymptotic gate...
We present a scalable and matrix-free eigensolver for studying two-level quantum spin chain models with nearest-neighbor XX +YY interactions plus Z terms. In particular, we focus on the Heisenberg interaction random on-site fields, model that is commonly used to study many-body localization (MBL) transition. This type of problem computationally challenging because vector space dimension grows exponentially physical system size, solve must be iterated many times average over different...
Achieving quantum computational advantage requires solving a classically intractable problem on device. Natural proposals rely upon the intrinsic hardness of simulating mechanics; however, verifying output is itself intractable. On other hand, certain algorithms (e.g. prime factorization via Shor's algorithm) are efficiently verifiable, but require more resources than what available near-term devices. One way to bridge gap between verifiability and implementation use "interactions" prover...
We present a compact quantum circuit for factoring large class of integers, including some whose classical hardness is expected to be equivalent RSA (but not integers themselves). To our knowledge, it the first polynomial-time achieve sublinear qubit count classically-hard problem; also achieves depth and nearly linear gate count. build on algorithm squarefree decomposition discovered by Li, Peng, Du Suter (Nature Scientific Reports 2012), which relies computing Jacobi symbol in...
Recently, quantum computing experiments have for the first time exceeded capability of classical computers to perform certain computations -- a milestone termed "quantum computational advantage." However, verifying output device in these required extremely large computations. An exciting next step demonstrating would be implement tests advantage with efficient verification, such that larger system sizes can tested and verified. One proposals an efficiently-verifiable test quantumness...
We propose several techniques to enhance the parallel scalability of a matrix-free eigensolver designed for studying many-body localization (MBL) quantum spin chain models with nearest-neighbor interactions and on-site disorder. This type problem is computationally challenging because dimension associated Hamiltonian matrix grows exponentially respect number spins L, we need average over different realizations random disorder obtain relevant statistical behavior. For each realization,...
A test of quantumness is a protocol that allows classical verifier to certify (only) prover not classical. We show tests follow certain template, which captures recent proposals such as (Kalai et al., 2022), can in fact do much more. Namely, the same protocols be used for certifying qubit, building-block stands at heart applications certifiable randomness and delegation quantum computation. Certifying qubits was previously only known possible based on hardness Learning with Errors problem...
In [Van Beeumen, et. al, HPC Asia 2020, https://www.doi.org/10.1145/3368474.3368497] a scalable and matrix-free eigensolver was proposed for studying the many-body localization (MBL) transition of two-level quantum spin chain models with nearest-neighbor $XX+YY$ interactions plus $Z$ terms. This type problem is computationally challenging because vector space dimension grows exponentially physical system size, averaging over different configurations random disorder needed to obtain relevant...