A Quantum Model for Entropic Springs

TL;DR

This paper introduces a quantum-mechanical model of a spin bath coupled to elastic materials, explaining entropic spring behavior and enabling the study of non-equilibrium quantum resonator states.

Contribution

It presents a novel quantum model that captures entropic spring phenomena and connects them to disordered media and low-temperature anomalies.

Findings

Reproduces entropic spring behavior

Applicable to disordered elastic media like glasses

Explains low-temperature specific heat and noise effects

Abstract

Motivated by understanding the emergence of thermodynamic restoring forces and oscillations, we develop a quantum-mechanical model of a bath of spins coupled to the elasticity of a material. We show our model reproduces the behavior of a variety of entropic springs while enabling investigation of non-equilibrium resonator states in the quantum domain. We find our model emerges naturally in disordered elastic media such as glasses, and is an additional, expected effect in systems with anomalous specific heat and 1/f noise at low temperatures due to two-level systems that fluctuate.