Spin-Dependent Quasiparticle Transport in Aluminum Single Electron Transistors

TL;DR

This paper studies how Zeeman-splitting influences spin-dependent quasiparticle transport in aluminum single-electron transistors, revealing regimes for spin filtering and the interplay of Coulomb blockade with spin effects.

Contribution

It introduces the analysis of spin-dependent transport in aluminum SETs under Zeeman-splitting, highlighting potential for bipolar spin filtering.

Findings

Identification of spin-dependent tunneling regimes

Proposal of device operation as a bipolar spin filter

Observation of Coulomb blockade effects with Zeeman-splitting

Abstract

We investigate the effect of Zeeman-splitting on quasiparticle transport in normal-superconducting-normal (NSN) aluminum single electron transistors (SETs). In the above-gap transport the interplay of Coulomb blockade and Zeeman-splitting leads to spin-dependence of the sequential tunneling. This creates regimes where either one or both spin species can tunnel onto or off the island. At lower biases, spin-dependence of the single quasiparticle state is studied and operation of the device as a bipolar spin filter is suggested.