Emulating many-body localization with a superconducting quantum processor

TL;DR

This paper demonstrates the emulation of many-body localization in a 10-qubit superconducting quantum processor, providing key signatures including entanglement growth, and advancing quantum simulation of complex many-body physics.

Contribution

It is the first experimental demonstration of many-body localization dynamics with a superconducting quantum processor, including direct observation of entanglement entropy growth.

Findings

Observation of long-time logarithmic entanglement growth

Detection of imbalance indicating non-ergodic behavior

Violation of eigenstate thermalization hypothesis

Abstract

The law of statistical physics dictates that generic closed quantum many-body systems initialized in nonequilibrium will thermalize under their own dynamics. However, the emergence of many-body localization (MBL) owing to the interplay between interaction and disorder, which is in stark contrast to Anderson localization that only addresses noninteracting particles in the presence of disorder, greatly challenges this concept because it prevents the systems from evolving to the ergodic thermalized state. One critical evidence of MBL is the long-time logarithmic growth of entanglement entropy, and a direct observation of it is still elusive due to the experimental challenges in multiqubit single-shot measurement and quantum state tomography. Here we present an experiment of fully emulating the MBL dynamics with a 10-qubit superconducting quantum processor, which represents a spin-1/2 XY model featuring programmable disorder and long-range spin-spin interactions. We provide essential signatures of MBL, such as the imbalance due to the initial nonequilibrium, the violation of eigenstate thermalization hypothesis, and, more importantly, the direct evidence of the long-time logarithmic growth of entanglement entropy. Our results lay solid foundations for precisely simulating the intriguing physics of quantum many-body systems on the platform of large-scale multiqubit superconducting quantum processors.