Single Quantum Level Electron Turnstile

TL;DR

This paper demonstrates a single-electron turnstile device using a quantum dot coupled to superconducting leads, showing improved quasiparticle immunity and narrow energy electron delivery, advancing quantum electron control.

Contribution

The paper introduces a novel superconductor-quantum dot-superconductor electron turnstile with enhanced quasiparticle immunity and energy precision over traditional designs.

Findings

Successful operation of a single-electron turnstile with superconducting leads.

Enhanced immunity to quasiparticle poisoning.

Electrons delivered with very narrow energy distribution.

Abstract

We report on the realization of a single-electron source, where current is transported through a single-level quantum dot (Q), tunnel-coupled to two superconducting leads (S). When driven with an ac gate voltage, the experiment demonstrates electron turnstile operation. Compared to the more conventional superconductor - normal metal - superconductor turnstile, our SQS device presents a number of novel properties, including higher immunity to the unavoidable presence of non-equilibrium quasiparticles in superconducting leads. In addition, we demonstrate its ability to deliver electrons with a very narrow energy distribution.