Small-world complex network generation on a digital quantum processor

Journal Article · 01 August 2022 · Nature Communications

DOI: https://doi.org/10.1038/s41467-022-32056-y · OSTI ID:1879551

Jones, Eric B. ; Hillberry, Logan E. ; Jones, Matthew T.; Fasihi, Mina; Roushan, Pedram; Jiang, Zhang; Ho, Alan; Neill, Charles ; Ostby, Eric; Graf, Peter; Kapit, Eliot; Carr, Lincoln D.

Abstract Quantum cellular automata (QCA) evolve qubits in a quantum circuit depending only on the states of their neighborhoods and model how rich physical complexity can emerge from a simple set of underlying dynamical rules. The inability of classical computers to simulate large quantum systems hinders the elucidation of quantum cellular automata, but quantum computers offer an ideal simulation platform. Here, we experimentally realize QCA on a digital quantum processor, simulating a one-dimensional Goldilocks rule on chains of up to 23 superconducting qubits. We calculate calibrated and error-mitigated population dynamics and complex network measures, which indicate the formation of small-world mutual information networks. These networks decohere at fixed circuit depth independent of system size, the largest of which corresponding to 1,056 two-qubit gates. Such computations may enable the employment of QCA in applications like the simulation of strongly-correlated matter or beyond-classical computational demonstrations.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE; USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1879551
• Report Number(s): NREL/JA-2C00-83524; 4483; PII: 32056
• Journal Information: Nature Communications, Journal Name: Nature Communications Journal Issue: 1 Vol. 13; ISSN 2041-1723
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United Kingdom
• Language: English