Error-corrected quantum annealing with hundreds of qubits.
Quantum information processing offers dramatic speedups, yet is susceptible to decoherence, whereby quantum superpositions decay into mutually exclusive classical alternatives, thus robbing quantum computers of their power. This makes the development of quantum error correction an essential aspect of quantum computing. So far, little is known about protection against decoherence for quantum annealing, a computational paradigm aiming to exploit ground-state quantum dynamics to solve optimization problems more rapidly than is possible classically. Here we develop error correction for quantum annealing and experimentally demonstrate it using antiferromagnetic chains with up to 344 superconducting flux qubits in processors that have recently been shown to physically implement programmable quantum annealing. We demonstrate a substantial improvement over the performance of the processors in the absence of error correction. These results pave the way towards large-scale noise-protected adiabatic quantum optimization devices, although a threshold theorem such as has been established in the circuit model of quantum computing remains elusive.
1] Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA [2] Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, California 90089, USA [3] Information Sciences Institute, University of Southern California, Marina del Rey, California 90292, USA.
Kristen L
KL
Pudenz
1] Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, California 90089, USA [2] Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA.
Tameem
T
Albash
1] Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA [2] Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, California 90089, USA [3] Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA [4] Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA.
Daniel A
DA
Lidar