Finite-time thermal refrigerator in interacting Bose-Einstein Condensates

TL;DR

This paper demonstrates a finite-time quantum refrigeration cycle using interacting Bose-Einstein condensates, achieving significant cooling and showing potential for practical quantum thermal devices.

Contribution

It introduces a numerical scheme for implementing a finite-time quantum refrigerator with BECs, including realistic initial states and dynamics, advancing quantum thermodynamics research.

Findings

Achieved ~20% cooling in the first cycle

Reached ~27% total cooling after two cycles

Demonstrated feasibility of finite-time refrigeration in BECs

Abstract

We study a finite-time thermodynamic refrigeration cycle realized numerically in three-dimensional, weakly interacting Bose-Einstein condensates (BECs). The setup consists of three spatially separated condensates -- system, piston, and reservoir -- coupled through time-dependent potential barriers that implement compression, expansion, and contact strokes. Finite-temperature initial states are generated with the Stochastic Ginzburg-Landau equation, and the subsequent dynamics are evolved using the truncated Gross-Pitaevskii equation. To measure temperatures we use a momentum-space thermometry method that provides estimates for each condensate. We find that despite mass transfer and sound excitations, the protocol achieves successful cooling during consecutive cycles: the first cycle lowers its temperature by ~20%, and a second cycle yields additional, though reduced, cooling, reaching a final ~27% cooling from the initial state. Our results show that interacting BECs can sustain finite-time quantum thermal cycles under realistic conditions, and provide a platform for exploring different refrigeration schemes, optimized control protocols, and shortcuts to adiabaticity.