7,028 research outputs found
Status and Future Perspectives for Lattice Gauge Theory Calculations to the Exascale and Beyond
In this and a set of companion whitepapers, the USQCD Collaboration lays out
a program of science and computing for lattice gauge theory. These whitepapers
describe how calculation using lattice QCD (and other gauge theories) can aid
the interpretation of ongoing and upcoming experiments in particle and nuclear
physics, as well as inspire new ones.Comment: 44 pages. 1 of USQCD whitepapers
Limits on Fundamental Limits to Computation
An indispensable part of our lives, computing has also become essential to
industries and governments. Steady improvements in computer hardware have been
supported by periodic doubling of transistor densities in integrated circuits
over the last fifty years. Such Moore scaling now requires increasingly heroic
efforts, stimulating research in alternative hardware and stirring controversy.
To help evaluate emerging technologies and enrich our understanding of
integrated-circuit scaling, we review fundamental limits to computation: in
manufacturing, energy, physical space, design and verification effort, and
algorithms. To outline what is achievable in principle and in practice, we
recall how some limits were circumvented, compare loose and tight limits. We
also point out that engineering difficulties encountered by emerging
technologies may indicate yet-unknown limits.Comment: 15 pages, 4 figures, 1 tabl
Quantum Computing in the NISQ era and beyond
Noisy Intermediate-Scale Quantum (NISQ) technology will be available in the
near future. Quantum computers with 50-100 qubits may be able to perform tasks
which surpass the capabilities of today's classical digital computers, but
noise in quantum gates will limit the size of quantum circuits that can be
executed reliably. NISQ devices will be useful tools for exploring many-body
quantum physics, and may have other useful applications, but the 100-qubit
quantum computer will not change the world right away --- we should regard it
as a significant step toward the more powerful quantum technologies of the
future. Quantum technologists should continue to strive for more accurate
quantum gates and, eventually, fully fault-tolerant quantum computing.Comment: 20 pages. Based on a Keynote Address at Quantum Computing for
Business, 5 December 2017. (v3) Formatted for publication in Quantum, minor
revision
Optimizing Quantum Error Correction Codes with Reinforcement Learning
Quantum error correction is widely thought to be the key to fault-tolerant
quantum computation. However, determining the most suited encoding for unknown
error channels or specific laboratory setups is highly challenging. Here, we
present a reinforcement learning framework for optimizing and fault-tolerantly
adapting quantum error correction codes. We consider a reinforcement learning
agent tasked with modifying a family of surface code quantum memories until a
desired logical error rate is reached. Using efficient simulations with about
70 data qubits with arbitrary connectivity, we demonstrate that such a
reinforcement learning agent can determine near-optimal solutions, in terms of
the number of data qubits, for various error models of interest. Moreover, we
show that agents trained on one setting are able to successfully transfer their
experience to different settings. This ability for transfer learning showcases
the inherent strengths of reinforcement learning and the applicability of our
approach for optimization from off-line simulations to on-line laboratory
settings.Comment: 21 pages, 13 figures, 1 table, updated reference list, accepted for
publication in Quantu
- …