Jiang Zhang
A5100422956- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Planetary Science and Exploration
- Astro and Planetary Science
- Quantum many-body systems
- Neural Networks and Reservoir Computing
- Physics of Superconductivity and Magnetism
- Cold Atom Physics and Bose-Einstein Condensates
- Space Science and Extraterrestrial Life
- Advancements in Semiconductor Devices and Circuit Design
- Quantum-Dot Cellular Automata
- Neural Networks and Applications
- Complex Network Analysis Techniques
- Quantum, superfluid, helium dynamics
- Wireless Signal Modulation Classification
- Nuclear physics research studies
- Stellar, planetary, and galactic studies
- Semiconductor materials and devices
- Quantum Mechanics and Applications
- Blind Source Separation Techniques
- Fire dynamics and safety research
- Isotope Analysis in Ecology
- Combustion and Detonation Processes
- Advanced Thermodynamics and Statistical Mechanics
Google (United States)
2019-2025
Shandong University
2014-2025
National University of Defense Technology
2018-2025
University of Southern California
2024
Beijing Normal University
2014-2024
Southern California University for Professional Studies
2024
Xi'an University of Science and Technology
2019-2023
Guangxi Normal University
2023
University of Electronic Science and Technology of China
2023
National University of Singapore
2020-2022
Abstract Practical quantum computing will require error rates well below those achievable with physical qubits. Quantum correction 1,2 offers a path to algorithmically relevant by encoding logical qubits within many qubits, for which increasing the number of enhances protection against errors. However, introducing more also increases sources, so density errors must be sufficiently low performance improve code size. Here we report measurement qubit scaling across several sizes, and...
Quantum simulation of chemistry and materials is predicted to be an important application for both near-term fault-tolerant quantum devices. However, at present, developing studying algorithms these problems can difficult due the prohibitive amount domain knowledge required in area algorithms. To help bridge this gap open field more researchers, we have developed OpenFermion software package (www.openfermion.org). open-source library written largely Python under Apache 2.0 license, aimed...
The discovery of topological order has revolutionized the understanding quantum matter in modern physics and provided theoretical foundation for many error correcting codes. Realizing topologically ordered states proven to be extremely challenging both condensed synthetic systems. Here, we prepare ground state toric code Hamiltonian using an efficient circuit on a superconducting processor. We measure entanglement entropy near expected value $\ln2$, simulate anyon interferometry extract...
Farhi et al. recently proposed a class of quantum algorithms, the approximate optimization algorithm (QAOA), for approximately solving combinatorial problems (E. al., arXiv:1411.4028; arXiv:1412.6062; arXiv:1602.07674). A level-$p$ QAOA circuit consists $p$ steps; in each step classical Hamiltonian, derived from cost function, is applied followed by mixing Hamiltonian. The $2p$ times which these two Hamiltonians are parameters algorithm, to be optimized classically best performance. As...
Abstract Quantum many-body systems display rich phase structure in their low-temperature equilibrium states 1 . However, much of nature is not thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium can exhibit novel dynamical phases 2–8 may otherwise be forbidden by thermodynamics, a paradigmatic example being the discrete time crystal (DTC) 7,9–15 Concretely, defined periodically driven many-body-localized (MBL) via concept eigenstate order 7,16,17 In...
Quantum algorithms offer a dramatic speedup for computational problems in material science and chemistry. However, any near-term realizations of these will need to be optimized fit within the finite resources offered by existing noisy hardware. Here, taking advantage adjustable coupling gmon qubits, we demonstrate continuous two-qubit gate set that can provide threefold reduction circuit depth as compared standard decomposition. We implement two families: an imaginary swap-like (iSWAP-like)...
Interaction in quantum systems can spread initially localized information into the many degrees of freedom entire system. Understanding this process, known as scrambling, is key to resolving various conundrums physics. Here, by measuring time-dependent evolution and fluctuation out-of-time-order correlators, we experimentally investigate dynamics scrambling on a 53-qubit processor. We engineer circuits that distinguish two mechanisms associated with operator spreading entanglement, observe...
Indistinguishability of particles is a fundamental principle quantum mechanics
Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin one-dimensional Heisenberg model were conjectured as to belong Kardar-Parisi-Zhang (KPZ) universality class based on scaling infinite-temperature spin-spin correlation function. a chain 46 superconducting qubits, we studied probability distribution magnetization transferred across chain's center, [Formula: see text]. The first two moments text] show superdiffusive...
Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for simulation of high-temperature superconductivity or magnetism. Using up 49 superconducting qubits, we prepared low-energy transverse-field Ising model through coupling auxiliary qubits. In one dimension, observed long-range correlations and a ground-state fidelity 0.86 18 qubits at critical point. two dimensions, found mutual information that extends beyond...
Undesired coupling to the surrounding environment destroys long-range correlations in quantum processors and hinders coherent evolution nominally available computational space. This noise is an outstanding challenge when leveraging computation power of near-term
Physical systems with strongly correlated electrons (fermions) are notoriously difficult to study using traditional computers. Meanwhile, as programmable $q\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}m$ computers become a reality, efficient (and preferably general) quantum algorithms needed, in the face of limited qubit-qubit connectivity near term. Addressing both problems, authors develop...
Inspired by a class of algorithms proposed Farhi et al. (arXiv:1411.4028), namely the quantum approximate optimization algorithm (QAOA), we present circuit-based to search for needle in haystack, obtaining same quadratic speedup achieved Grover's original algorithm. In our algorithm, problem Hamiltonian (oracle) and transverse field are applied alternately system periodic manner. We introduce technique, based on spin-coherent states, analyze composite unitary single period. This drives...
With the rapid developments in quantum hardware comes a push towards first practical applications on these devices. While fully fault-tolerant computers may still be years away, one ask if there exist intermediate forms of error correction or mitigation that might enable before then. In this work, we consider idea post-processing decoders using existing codes, which are capable mitigating errors encoded logical qubits classical with no complicated syndrome measurements additional beyond...
Abstract The chemical compositions of relatively young mare lava flows have implications for the late volcanism on Moon. Here we report composition soil along rim a 450-m diameter fresh crater at Chang′e-3 (CE-3) landing site, investigated by Yutu rover with in situ APXS (Active Particle-induced X-ray Spectrometer) and VNIS (Visible Near-infrared Imaging measurements. Results indicate that this region's differs from other sample-return sites is new type basalt not previously sampled, but...
Quantum Neural Networks (QNNs) are a promising variational learning paradigm with applications to near-term quantum processors, however they still face some significant challenges. One such challenge is finding good parameter initialization heuristics that ensure rapid and consistent convergence local minima of the parameterized circuit landscape. In this work, we train classical neural networks assist in process, also know as meta-learning, rapidly find approximate optima landscape for...
The tunneling between the two ground states of an Ising ferromagnet is a typical example many-body processes local minima, as they occur during quantum annealing. Performing Monte Carlo (QMC) simulations we find that QMC rate displays same scaling with system size, incoherent tunneling. in both cases $O(\Delta^2)$, where $\Delta$ splitting. An important consequence can be used to predict performance annealer for through barrier. Furthermore, by using open instead periodic boundary conditions...
Abstract Variational algorithms are a promising paradigm for utilizing near-term quantum devices modeling electronic states of molecular systems. However, previous bounds on the measurement time required have suggested that application these techniques to larger molecules might be infeasible. We present strategy based low-rank factorization two-electron integral tensor. Our approach provides cubic reduction in term groupings over prior state-of-the-art and enables times three orders...
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these on computers may avoid the prohibitively high computational cost incurred in classical approaches. However, systematic errors and decoherence effects presented current devices make it difficult achieve this. Here, we simulate dynamics of one-dimensional Fermi-Hubbard model using 16 qubits a digital superconducting processor. We observe separations...