Quantum Divide and Compute: Hardware Demonstrations and Noisy Simulations

Conference · Wed Jan 01 00:00:00 EST 2020

DOI:https://doi.org/10.1109/ISVLSI49217.2020.00034· OSTI ID:1804088

Ayral, Thomas; Le Regent, Francois-Marie; Saleem, Zain; Alexeev, Yuri; Suchara, Martin

Noisy, intermediate-scale quantum computers come with intrinsic limitations in terms of the number of qubits (circuit "width") and decoherence time (circuit "depth") they can have. Here, for the first time, we demonstrate a recently introduced method that breaks a circuit into smaller subcircuits or fragments, and thus makes it possible to run circuits that are either too wide or too deep for a given quantum processor. We investigate the behavior of the method on one of IBM's 20-qubit superconducting quantum processors with various numbers of qubits and fragments. We build noise models that capture decoherence, readout error, and gate imperfections for this particular processor. We then carry out noisy simulations of the method in order to account for the observed experimental results. We find an agreement within 20% between the experimental and the simulated success probabilities, and we observe that recombining noisy fragments yields overall results that can outperform the results without fragmentation.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1804088
• Resource Relation: Conference: 2020 IEEE Computer Society Annual Symposium on VLSI, 07/06/20 - 07/08/20, Limassol, CY
• Country of Publication: United States
• Language: English