Radio-Frequency Single-Electron Refrigerator

TL;DR

This paper introduces a novel cyclic refrigeration method using mesoscopic electron transport in a Coulomb-blockaded device, achieving efficient cooling powered by electron tunneling and electrostatic work, with practical implementation considerations.

Contribution

It proposes a new refrigeration principle based on synchronized electron tunneling in a Coulomb-blockaded device, demonstrating potential for efficient cooling at mesoscopic scales.

Findings

Cooling power scales with cycle frequency as ~k_B T × f

Efficiency is approximately ~k_B T / Δ, with Δ being the superconducting gap

Performance remains robust against non-idealities like offset charges

Abstract

We propose a cyclic refrigeration principle based on mesoscopic electron transport. Synchronous sequential tunnelling of electrons in a Coulomb-blockaded device, a normal metal-superconductor single-electron box, results in a cooling power of $\sim k_{\rm B}T \times f$ at temperature $T$ over a wide range of cycle frequencies $f$. Electrostatic work, done by the gate voltage source, removes heat from the Coulomb island with an efficiency of $\sim k_{\rm B}T/\Delta$, where $\Delta$ is the superconducting gap. The performance is not affected significantly by non-idealities, for instance by offset charges. We propose ways of characterizing the system and of its practical implementation.