Quantum irreversibility of quasistatic protocols for finite-size quantized systems

TL;DR

This paper investigates quantum irreversibility in finite-size, quantized systems under quasistatic protocols, revealing a crossover from adiabatic behavior to chaos-assisted depletion and quantum fluctuations, challenging classical and simplified models.

Contribution

It demonstrates the dominance of chaos-assisted processes and quantum fluctuations in quantum irreversibility, highlighting limitations of the two-orbital approximation and Landau-Zener paradigm.

Findings

Crossover from adiabatic to chaos-dominated regime as sweep rate decreases

Breakdown of quantum-to-classical correspondence in the slow limit

Failure of two-orbital approximation to capture key dynamics

Abstract

Quantum mechanically, a driving process is expected to be reversible in the quasistatic limit, also known as the adiabatic theorem. This statement stands in opposition to classical mechanics, where a mix of regular and chaotic dynamics implies irreversibility. A paradigm for demonstrating the signatures of chaos in quantum irreversibility is a sweep process whose objective is to transfer condensed bosons from a source orbital. We show that such a protocol is dominated by an interplay of adiabatic-shuttling and chaos-assisted depletion processes. The latter is implied by interaction terms that spoil the Bogoliubov integrability of the Hamiltonian. As the sweep rate is lowered, a crossover to a regime that is dominated by quantum fluctuations is encountered, featuring a breakdown of quantum-to-classical correspondence. The major aspects of this picture are not captured by the common two-orbital approximation, which implies failure of the familiar many-body Landau-Zener paradigm.