Austin G. Fowler
A5010185866- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum and electron transport phenomena
- Quantum-Dot Cellular Automata
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor materials and devices
- Advanced Data Storage Technologies
- Quantum many-body systems
- Neural Networks and Reservoir Computing
- Physics of Superconductivity and Magnetism
- Quantum Mechanics and Applications
- Parallel Computing and Optimization Techniques
- Low-power high-performance VLSI design
- Advanced Memory and Neural Computing
- graph theory and CDMA systems
- Optical Network Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Surface and Thin Film Phenomena
- Computability, Logic, AI Algorithms
- Quantum optics and atomic interactions
- Error Correcting Code Techniques
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Advanced Thermodynamics and Statistical Mechanics
- Advanced Frequency and Time Standards
Google (United States)
2015-2024
University of California, Riverside
2022
California State University, Bakersfield
2021
University of Minnesota, Duluth
2019
Centre for Quantum Computation and Communication Technology
2003-2015
The University of Melbourne
2004-2015
University of California, Santa Barbara
2013-2015
University of Newcastle Australia
2013
University of Waterloo
2007-2009
IBM (United States)
1991
This article provides an introduction to surface code quantum computing. We first estimate the size and speed of a computer. then introduce concept stabilizer, using two qubits, extend this stabilizers acting on two-dimensional array physical which we implement code. next describe how logical qubits are formed in give numerical estimates their fault-tolerance. outline physically moved array, qubit braid transformations constructed, between is equivalent controlled-NOT. single-qubit Hadamard,...
We report the first electronic structure calculation performed on a quantum computer without exponentially costly precompilation. use programmable array of superconducting qubits to compute energy surface molecular hydrogen using two distinct algorithms. First, we experimentally execute unitary coupled cluster method variational eigensolver. Our efficient implementation predicts correct dissociation within chemical accuracy numerically exact result. Second, demonstrate canonical algorithm...
As the search continues for useful applications of noisy intermediate scale quantum devices, variational simulations fermionic systems remain one most promising directions. Here, we perform a series chemistry largest which involved dozen qubits, 78 two-qubit gates, and 114 one-qubit gates. We model binding energy ${\rm H}_6$, H}_8$, H}_{10}$ H}_{12}$ chains as well isomerization diazene. also demonstrate error-mitigation strategies based on $N$-representability dramatically improve effective...
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...
A key step toward demonstrating a quantum system that can address difficult problems in physics and chemistry will be performing computation beyond the capabilities of any classical computer, thus achieving so-called supremacy. In this study, we used nine superconducting qubits to demonstrate promising path By individually tuning qubit parameters, were able generate thousands distinct Hamiltonian evolutions probe output probabilities. The measured probabilities obey universal distribution,...
We present a comprehensive and self-contained simplified review of the quantum computing scheme Phys. Rev. Lett. 98, 190504 (2007), which features 2-D nearest neighbor coupled lattice qubits, threshold error rate approaching 1%, natural asymmetric adjustable strength correction low overhead arbitrarily long-range logical gates. These make it by far best most practical devised to date. restrict discussion direct manipulation surface code using stabilizer formalism, both we also briefly...
Putting photons to work Interacting quantum particles can behave in peculiar ways. To understand that behavior, physicists have turned simulation, which a tunable and clean system be monitored as it evolves under the influence of interactions. Roushan et al. used chain nine superconducting qubits create effective interactions between normally noninteracting directly measured energy levels their system. The interplay disorder gave rise transition localized state. With an increase number...
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...
Large-scale quantum computation will only be achieved if experimentally implementable error correction procedures are devised that can tolerate achievable rates. We describe a procedure requires 2-D square lattice of qubits interact with their nearest neighbors, yet gate rates over 1%. The precise maximum tolerable rate depends on the model, and we calculate values in range 1.1--1.4% for various physically reasonable models. Even lowest value represents highest threshold calculated to date...
Simulating quantum physics with a device which itself is mechanical, notion Richard Feynman originated, would be an unparallelled computational resource. However, the universal simulation of fermionic systems daunting due to their particle statistics, and left as open question whether it could done, because need for non-local control. Here, we implement interactions digital techniques in superconducting circuit. Focusing on Hubbard model, perform time evolution constant well dynamic phase...
We develop a layered quantum computer architecture, which is systematic framework for tackling the individual challenges of developing while constructing cohesive device design. discuss many prominent techniques implementing circuit-model computing and introduce several new methods, with an emphasis on employing surface code error correction. In doing so, we propose architecture based optical control dots. The timescales physical hardware operations logical, error-corrected gates differ by...
Realizing the potential of quantum computing requires sufficiently low logical error rates1. Many applications call for rates as 10-15 (refs. 2-9), but state-of-the-art platforms typically have physical near 10-3 10-14). Quantum correction15-17 promises to bridge this divide by distributing information across many qubits in such a way that errors can be detected and corrected. Errors on encoded qubit state exponentially suppressed number grows, provided are below certain threshold stable...
Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity gates and extensibility to modest system sizes. Nonetheless, outstanding challenge is stabilizing their energy-relaxation times, which can fluctuate unpredictably in frequency time. Here, we use as spectral temporal probes of individual two-level-system defects provide direct evidence that responsible the largest fluctuations. This research lays foundation qubit performance...
The availability of a universal quantum computer may have fundamental impact on vast number research fields and society as whole. An increasingly large scientific industrial community is working toward the realization such device. arbitrarily best be constructed using modular approach. We present blueprint for trapped ion-based scalable module, making it possible to create architecture based long-wavelength radiation gates. modules control all operations stand-alone units, are silicon...
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)...
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...
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...
We present a method for optimizing quantum control in experimental systems, using subset of randomized benchmarking measurements to rapidly infer error. This is demonstrated improve single- and two-qubit gates, minimize gate bleedthrough, where mechanism can cause errors on subsequent identify crosstalk superconducting qubits. able correct parameters so that no longer dominate suitable automated closed-loop optimization systems.