TY - JOUR
T1 - In situ upgrade of quantum simulators to universal computers
AU - Dive, Benjamin
AU - Pitchford, Alexander
AU - Mintert, Florian
AU - Burgarth, Daniel
N1 - Funding Information:
This work was supported by EPSRC through the Quantum Controlled Dynamics Centre for Doctoral Training, the EPSRC Grant No. EP/M01634X/1, and the ERC Project ODYC-QUENT. We are grateful to HPC Wales for giving access to the cluster that was used to perform the numerical simulations. Many thanks to Stephen Glaser and David Leiner for discussions on possible implementations.
Publisher Copyright:
© 2017 Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2018/8/8
Y1 - 2018/8/8
N2 - Quantum simulators, machines that can replicate the dynamics of quantum systems, are being built as useful devices and are seen as a stepping stone to universal quantum computers. A key difference between the two is that computers have the ability to perform the logic gates that make up algorithms. We propose a method for learning how to construct these gates efficiently by using the simulator to perform optimal control on itself. This bypasses two major problems of purely classical approaches to the control problem: the need to have an accurate model of the system, and a classical computer more powerful than the quantum one to carry out the required simulations. Strong evidence that the scheme scales polynomially in the number of qubits, for systems of up to 9 qubits with Ising interactions, is presented from numerical simulations carried out in different topologies. This suggests that this in situ approach is a practical way of upgrading quantum simulators to computers.
AB - Quantum simulators, machines that can replicate the dynamics of quantum systems, are being built as useful devices and are seen as a stepping stone to universal quantum computers. A key difference between the two is that computers have the ability to perform the logic gates that make up algorithms. We propose a method for learning how to construct these gates efficiently by using the simulator to perform optimal control on itself. This bypasses two major problems of purely classical approaches to the control problem: the need to have an accurate model of the system, and a classical computer more powerful than the quantum one to carry out the required simulations. Strong evidence that the scheme scales polynomially in the number of qubits, for systems of up to 9 qubits with Ising interactions, is presented from numerical simulations carried out in different topologies. This suggests that this in situ approach is a practical way of upgrading quantum simulators to computers.
UR - http://www.scopus.com/inward/record.url?scp=85094878606&partnerID=8YFLogxK
U2 - 10.22331/q-2018-08-08-80
DO - 10.22331/q-2018-08-08-80
M3 - Article
AN - SCOPUS:85094878606
SN - 2521-327X
VL - 2
JO - Quantum
JF - Quantum
ER -