Phase-driven charge manipulation in Hybrid Single-Electron Transistor

TL;DR

This paper introduces a phase-driven hybrid single-electron transistor that uses magnetic flux to control charge states, enabling potential applications in quantum metrology and single-electron manipulation.

Contribution

It presents a novel device design that employs phase-tunable superconducting gaps for charge control, realized with standard nanotechniques.

Findings

Charge state control via magnetic flux in the device.

Energy barriers modulated by superconducting gaps influence charge transport.

Device compatible with existing superconducting electronics.

Abstract

Phase-tunable hybrid devices, built upon nanostructures combining normal metal and superconductors, have been the subject of intense studies due to their numerous combinations of different charge and heat transport configurations. They exhibit solid applications in quantum metrology and coherent caloritronics. Here we propose and realize a new kind of hybrid device with potential application in single charge manipulation and quantized current generation. We show that by tuning superconductivity on two proximized nanowires, coupled via a Coulombic normal metal island, we are able to control its charge state configuration. This device supports a one-control-parameter-cycle being actuated by the sole magnetic flux. In a voltage biased regime, the phase-tunable superconducting gaps can act as energy barriers for charge quanta leading to an additional degree of freedom in single electronics. The resulting configuration is fully electrostatic and the current across the device is governed by the quasiparticle populations in the source and drain leads. Notably, the proposed device can be realized using standard nanotechniques opening the possibility to a straightforward coupling with the nowadays well developed superconducting electronics.