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arXiv · 2405.14935

Arresting Quantum Chaos Dynamically in Transmon Arrays

Rohit Mukherjee·Haoyu Guo·Keiran Lewellen·Debanjan Chowdhury
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Abstract

Ergodic quantum many-body systems evolving under unitary time dynamics typically lose memory of their initial state via information scrambling. Here we consider a paradigmatic translationally invariant many-body Hamiltonian of interacting bosons -- a Josephson junction array in the transmon regime -- in the presence of a strong Floquet drive. Generically, such a time-dependent drive is expected to heat the system to an effectively infinite temperature, featureless state in the late-time limit. However, using numerical exact-diagonalization we find evidence of special ratios of the drive amplitude and frequency where the system develops {\it emergent} conservation laws, and {\it approximate} integrability. Remarkably, at these same set of points, the Lyapunov exponent associated with the semi-classical dynamics for the coupled many-body equations of motion drops by orders of magnitude, arresting the growth of chaos. We supplement our numerical results with an analytical Floquet-Magnus expansion that includes higher-order corrections, and capture the slow dynamics that controls decay away from exact freezing.

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Rohit Mukherjee, Haoyu Guo, Keiran Lewellen, Debanjan Chowdhury. 2024-05-23. Arresting Quantum Chaos Dynamically in Transmon Arrays. https://doi.org/10.1016/j.newton.2025.100011

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