Open Quantum Rotors: Connecting Correlations and Physical Currents

TL;DR

This paper investigates a chain of quantum rotors coupled to thermal baths, demonstrating that chiral interactions induce a quantum motor effect, especially near quantum phase transitions where quantum coherence and correlations are maximized.

Contribution

It introduces a model of quantum rotors with chiral interactions acting as an autonomous thermal motor, linking quantum correlations to motor efficiency.

Findings

Chiral interactions enable heat-to-rotation conversion.

Maximum quantum coherence correlates with optimal motor performance.

Quantum phase transitions enhance the system's dynamical response.

Abstract

We consider a finite one-dimensional chain of quantum rotors interacting with a set of thermal baths at different temperatures. When the interaction between the rotors is made chiral, such a system behaves as an autonomous thermal motor, converting heat currents into non-vanishing rotational ones. Such a dynamical response is strongly pronounced in the range of the Hamiltonian parameters for which the ground state of the system in the thermodynamic limit exhibits a quantum phase transition. Such working points are associated with large quantum coherence and multipartite quantum correlations within the state of the system. This suggests that the optimal operating regime of such quantum autonomous motor is one of maximal quantumness.