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arXiv · 2506.21061

Characterizing Many-body Dynamics with Projected Ensembles on a Superconducting Quantum Processor

Zhiguang Yan·Zi-Yong Ge·Rui Li·Yu-Ran Zhang·Franco Nori·Yasunobu Nakamura
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Abstract

Quantum simulators offer a new opportunity for the experimental exploration of non-equilibrium quantum many-body dynamics, which have traditionally been characterized through expectation values or entanglement measures, based on density matrices of the system. Recently, a more general framework for studying quantum many-body systems based on projected ensembles has been introduced, revealing novel quantum phenomena, such as deep thermalization in chaotic systems. Here, we experimentally investigate a chaotic quantum many-body system using projected ensembles on a superconducting processor with 16 qubits on a square lattice. Our results provide direct evidence of deep thermalization by observing a Haar-distributed projected ensemble for the steady states within a charge-conserved sector. Moreover, by introducing an ensemble-averaged entropy as a metric, we establish a benchmark for many-body information leakage from the system to its environment. Our work paves the way for studying quantum many-body dynamics using projected ensembles and shows a potential implication for advancing quantum simulation techniques.

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Zhiguang Yan, Zi-Yong Ge, Rui Li, Yu-Ran Zhang, Franco Nori, Yasunobu Nakamura. 2025-06-26. Characterizing Many-body Dynamics with Projected Ensembles on a Superconducting Quantum Processor. https://arxiv.org/abs/2506.21061

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