Electron subband degeneracy heat pump for cryogenic cooling

TL;DR

This paper proposes a novel solid-state cryogenic cooling method using electron subband degeneracy in semiconductor heterostructures, modeled as an electrostatic heat pump capable of reaching sub-dilution temperatures.

Contribution

It introduces a new electrostatic heat pump concept based on electron subband manipulation for cryogenic cooling, with theoretical modeling and estimated performance metrics.

Findings

Cooling power estimated at 4.5 mW/cm^3 at 300 mK

Fundamental limit set by electron-phonon interaction

Potential applications in quantum computing and infrared detection

Abstract

An unconventional method of continuous solid-state cryogenic cooling utilizing the electron subband degeneracy of semiconductor heterostructures is proposed in this Letter. An electrostatic heat pump is modeled, which employs subband "expansion" and "compression" to reach sub-dilution refrigeration temperatures with the fundamental limit set by electron-phonon interaction. Using an ultra-wide GaAs quantum well as an example, the cooling power per unit volume is estimated to reach $4.5\ \rm mW/cm^3$ with a hot-side temperature of $300\ \rm mK$, suitable for applications such as quantum computers or infrared detectors.