Realization of a discrete time crystal on 57 qubits of a quantum computer

作者：Philipp Frey, Stephan Rachel · 发表于：Science Advances · 年份：2022 · DOI：10.1126/sciadv.abm7652 · 被引用次数：162 · 研究领域：Quantum many-body systems、Quantum Computing Algorithms and Architecture、Quantum Information and Cryptography

Unconventional dynamical phases that violate ergodicity have been a subject of extensive research in recent years. A periodically driven system is naively expected to lose all memory of its initial state due to thermalization, yet this can be avoided in the presence of many-body localization. A discrete time crystal represents a driven system whose local observables spontaneously break time translation symmetry and retain memory of the initial state indefinitely. Here, we report the observation of a discrete time crystal on a chain consisting of 57 superconducting qubits on a state-of-the-art quantum computer. We probe random initial states and compare the cases of vanishing and finite disorder to distinguish many-body localization from prethermal dynamics. We further report results on the dynamical phase transition between the discrete time crystal and a thermal regime, which is observed via critical fluctuations in the system's subharmonic frequency response and a substantial speedup of spin depolarization.