Inducing Heat Reversal in a Three-Qubit Spin Chain

TL;DR

This paper demonstrates that initial quantum correlations in a three-qubit chain can induce a reversal of heat flow, defying classical thermodynamics, using quantum computer simulations.

Contribution

It introduces a method to control heat flow direction in a quantum system via initial correlations, showcasing non-classical heat reversal in a three-qubit chain.

Findings

Quantum correlations can reverse heat flow direction.

Initial correlations influence heat transfer dynamics.

Exotic heat pumping behavior observed in simulations.

Abstract

By the standard second law of thermodynamics, heat spontaneously flows from a hotter body to a colder body. However, quantum systems in which quantum correlations play a prominent role can exhibit a non-classical reversal of such heat flow. We propose a quantum system consisting of a chain of qubits, each in local Gibbs states, where only adjacent qubits are allowed to thermally interact. By controlling initial quantum correlations along the chain, we then demonstrate non-classical heat reversal for the special case of a three-qubit chain on a quantum computer. We explore multiple initial conditions for the spin chain to showcase exotic behaviour such as the preferential pumping of heat afforded by unequal initial correlations between adjacent pairs of qubits, reinforcing the role that initial correlations play in influencing the dynamics of heat flow.