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arXiv · 2211.05803

Observation of many-body Fock space dynamics in two dimensions

Yunyan Yao·Liang Xiang·Zexian Guo·Zehang Bao·Yong-Feng Yang·Zixuan Song·Haohai Shi·Xuhao Zhu·Feitong Jin·Jiachen Chen·Shibo Xu·Zitian Zhu·Fanhao Shen·Ning Wang·Chuanyu Zhang·Yaozu Wu·Yiren Zou·Pengfei Zhang·Hekang Li·Zhen Wang·Chao Song·Chen Cheng·Rubem Mondaini·H. Wang·J. Q. You·Shi-Yao Zhu·Lei Ying·Qiujiang Guo
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Abstract

Quantum many-body simulation provides a straightforward way to understand fundamental physics and connect with quantum information applications. However, suffering from exponentially growing Hilbert space size, characterization in terms of few-body probes in real space is often insufficient to tackle challenging problems such as quantum critical behavior and many-body localization (MBL) in higher dimensions. Here, we experimentally employ a new paradigm on a superconducting quantum processor, exploring such elusive questions from a Fock space view: mapping the many-body system onto an unconventional Anderson model on a complex Fock space network of many-body states. By observing the wave packet propagating in Fock space and the emergence of a statistical ergodic ensemble, we reveal a fresh picture for characterizing representative many-body dynamics: thermalization, localization, and scarring. In addition, we observe a quantum critical regime of anomalously enhanced wave packet width and deduce a critical point from the maximum wave packet fluctuations, which lend support for the two-dimensional MBL transition in finite-sized systems. Our work unveils a new perspective of exploring many-body physics in Fock space, demonstrating its practical applications on contentious MBL aspects such as criticality and dimensionality. Moreover, the entire protocol is universal and scalable, paving the way to finally solve a broader range of controversial many-body problems on future larger quantum devices.

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Yunyan Yao, Liang Xiang, Zexian Guo, Zehang Bao, Yong-Feng Yang, Zixuan Song, Haohai Shi, Xuhao Zhu, Feitong Jin, Jiachen Chen, Shibo Xu, Zitian Zhu, Fanhao Shen, Ning Wang, Chuanyu Zhang, Yaozu Wu, Yiren Zou, Pengfei Zhang, Hekang Li, Zhen Wang, Chao Song, Chen Cheng, Rubem Mondaini, H. Wang, J. Q. You, Shi-Yao Zhu, Lei Ying, Qiujiang Guo. 2022-11-10. Observation of many-body Fock space dynamics in two dimensions. https://doi.org/10.1038/s41567-023-02133-0

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