Thermodynamics of a minimal algorithmic cooling refrigerator

TL;DR

This paper explores the thermodynamic efficiency and performance limits of a minimal three-qubit quantum refrigerator, combining theoretical analysis with experimental validation in a nitrogen-vacancy center system.

Contribution

It provides the first combined theoretical and experimental study of a minimal three-qubit quantum cooling device, including performance bounds and practical implementation insights.

Findings

Analytical expressions for performance metrics including COP, cooling power, and polarization.

Experimental demonstration of approaching theoretical performance bounds.

Identification of fundamental upper limits in ideal reversible conditions.

Abstract

We investigate, theoretically and experimentally, the thermodynamic performance of a minimal three-qubit heat-bath algorithmic cooling refrigerator. We analytically compute the coefficient of performance, the cooling power and the polarization of the target qubit for an arbitrary number of cycles, taking realistic experimental imperfections into account. We determine their fundamental upper bounds in the ideal reversible limit and show that these values may be experimentally approached using a system of three qubits in a nitrogen-vacancy center in diamond.