Small quantum networks operating as quantum thermodynamic machines

TL;DR

This paper demonstrates that a 3-qubit system can function as a quantum thermodynamic machine, performing Carnot cycles and exhibiting a temperature-dependent work exchange sign flip, bridging quantum information and thermodynamics.

Contribution

It introduces a novel application of a 3-qubit system as a quantum thermodynamic machine driven in finite time, connecting quantum information systems with thermodynamic cycle implementation.

Findings

The 3-qubit chain can operate as a thermodynamic machine exchanging work.

The work sign flips at a critical temperature difference.

The system performs Carnot cycles in a quantum setting.

Abstract

We show that a 3-qubit system as studied for quantum information purposes can alternatively be used as a thermodynamic machine when driven in finite time and interfaced between two split baths. The spins are arranged in a chain where the working spin in the middle exercises Carnot cycles the area of which defines the exchanged work. The cycle orientation (sign of the exchanged work) flips as the difference of bath temperatures goes through a critical value.