Realistic non-local refrigeration engine based on Coulomb coupled systems

Abstract

Employing Coulomb-coupled systems, we demonstrate a cryogenic non-local refrigeration engine, that circumvents the need for a change in the energy resolved system-to-reservoir coupling, demanded by the recently proposed non-local refrigerators [1][2][3][4][5]. We demonstrate that an intentionally introduced energy difference between the ground states of adjacent tunnel coupled quantum dots, associated with Coulomb coupling, is sufficient to extract heat from a remote target reservoir. Investigating the performance and operating regime using quantum-master-equation (QME) approach, we point out to some crucial aspects of the proposed refrigeration engine. In particular, we demonstrate that the maximum cooling power for the proposed set-up is limited to about 70% of the optimal design. Proceeding further, we point out that to achieve a target reservoir temperature, lower compared to the average temperature of the current path, the applied voltage must be greater than a given threshold voltage VT H , that increases with decrease in the target reservoir temperature. In addition, we demonstrate that the maximum cooling power, as well as the coefficient of performance deteriorates as one approaches a lower target reservoir temperature. The novelty of the proposed refrigeration engine is the integration of fabrication simplicity along with descent cooling power. The idea proposed in this paper may pave the way towards the realization of efficient non-local cryogenic refrigeration systems.

A non-local cryogenic thermometer based on Coulomb-coupled systems

“…Engineering devices to couple heat with electrically measurable quantities has been extremely difficult in the domain of solid-state nano-technology. In the aspect of thermally controlled electrical transport in nano-scale systems; thermoelectric engines , refrigerators [27][28][29][30][31][32][33][34][35][36][37][38], rectifiers [39][40][41][42][43][44] and transistors [45][46][47][48][49][50][51][52] have been proposed in the last decade. Recently, the provision towards non-local thermal control of electrical transport, where electrical variables between two terminals are manipulated via thermal action at a remote third terminal, has been proposed and realized experimentally [53][54][55][56][57][58][59][60][61][62][63][64][65].…”