Quantum aging in mean-field models

TL;DR

This paper investigates the real-time dynamics of quantum mean-field models with long-range interactions, revealing how quantum fluctuations influence phase transitions and aging behavior, and extending fluctuation-dissipation relations to nonequilibrium conditions.

Contribution

It introduces a detailed analysis of quantum aging in mean-field models and extends the fluctuation-dissipation theorem to nonequilibrium quantum systems.

Findings

Quantum fluctuations lower the transition temperature.

Two distinct aging regimes are identified in the dynamics.

The classical limit is recovered as Planck's constant approaches zero.

Abstract

We study the real-time dynamics of quantum models with long-range interactions coupled to a heat-bath within the closed-time path-integral formalism. We show that quantum fluctuations depress the transition temperature. In the subcritical region there are two asymptotic time-regimes with (i) stationary, and (ii) slow aging dynamics. We extend the quantum fluctuation-dissipation theorem to the nonequilibrium case in a consistent way with the notion of an effective temperature that drives the system in the aging regime. The classical results are recovered for $\hbar\to 0$.