A Dynamical Study of the Quantum p=2 Spherical Model

TL;DR

This paper investigates the long-time dynamics of the disordered quantum p=2 spherical model, analyzing phase behavior, quantum criticality, and fluctuation-dissipation relations across different parameters.

Contribution

It provides a detailed dynamical analysis of the quantum p=2 spherical model, including phase characterization and the identification of a quantum critical point.

Findings

Identification of paramagnetic and coarsened regions.

Existence of a quantum critical point at zero temperature.

Verification that fluctuation-dissipation theorem holds in stationary regime.

Abstract

We present a dynamical study of the disordered quantum p=2 spherical model at long times. Its phase behavior as a function of spin-bath coupling, strength of quantum fluctuations and temperature is characterized, and we identify different paramagnetic and coarsened regions. A quantum critical point at zero temperature in the limit of vanishing dissipation is also found. Furthermore we show analytically that the fluctuation-dissipation theorem is obeyed in the stationary regime.