Probing quantum chaos in multipartite systems

TL;DR

This paper investigates how quantum chaos manifests in multipartite systems by analyzing full counting statistics of energies, revealing the interplay between local chaos and global behavior, and demonstrating suppression of chaos at strong coupling.

Contribution

It introduces a method to probe quantum chaos through full counting statistics and explores how interactions affect chaos in multipartite systems, including experimental feasibility.

Findings

Signatures of quantum chaos appear as dip-ramp-plateau in the characteristic function.

Global chaos can be suppressed at strong coupling in certain models.

The approach is suitable for experimental implementation with single-qubit interferometry.

Abstract

Understanding the emergence of quantum chaos in multipartite systems is challenging in the presence of interactions. We show that the contribution of the subsystems to the global behavior can be revealed by probing the full counting statistics of the local, total, and interaction energies. As in the spectral form factor, signatures of quantum chaos in the time domain dictate a dip-ramp-plateau structure in the characteristic function, i.e., the Fourier transform of the eigenvalue distribution. With this approach, we explore the fate of chaos in interacting subsystems that are locally maximally chaotic. Global quantum chaos can be suppressed at strong coupling, as illustrated with coupled copies of random-matrix Hamiltonians and of the Sachdev-Ye-Kitaev model. Our method is amenable to experimental implementation using single-qubit interferometry.