Thermofield dynamics: Quantum Chaos versus Decoherence

TL;DR

This paper explores how quantum chaos signatures in thermofield dynamics are affected by decoherence, revealing the interplay between spectral correlations, information loss, and chaotic behavior in many-body systems.

Contribution

It analyzes the impact of decoherence on quantum chaos signatures within thermofield dynamics, highlighting the competition among decoherence, spectral features, and information loss.

Findings

Decoherence delays the spectral dip and shortens the linear ramp.

Energy dephasing suppresses quantum noise fluctuations.

The interplay is demonstrated in the stochastic Sachdev-Ye-Kitaev model.

Abstract

Quantum chaos imposes universal spectral signatures that govern the thermofield dynamics of a many-body system in isolation. The fidelity between the initial and time-evolving thermofield double states exhibits as a function of time a decay, dip, ramp and plateau. Sources of decoherence give rise to a nonunitary evolution and result in information loss. Energy dephasing gradually suppresses quantum noise fluctuations and the dip associated with spectral correlations. Decoherence further delays the appearance of the dip and shortens the span of the linear ramp associated with chaotic behavior. The interplay between signatures of quantum chaos and information loss is determined by the competition among the decoherence, dip and plateau characteristic times, as demoonstrated in the stochastic Sachdev-Ye-Kitaev model.