Flux pumping of Cooper pairs through a Josephson Energy-Suppression Pump

TL;DR

This paper introduces a magnetic flux-controlled Josephson-Energy Suppression Pump that enables efficient Cooper pair pumping by collapsing Cooper condensates in superconducting nanowires, reducing leakage current without gate modulation.

Contribution

It presents a novel Josephson-Energy Suppression Pump controlled solely by magnetic flux, enhancing Cooper pair pumping efficiency and reducing leakage current.

Findings

Magnetic flux can fully suppress Josephson energies in the device.

The pump operates effectively without gate modulation.

Non-adiabatic pumping performance is characterized.

Abstract

In this paper, we propose a novel kind of Josephson-Energy Suppression Pump (JESP) controlled by a fully magnetic flux drive. The device presented here is composed of two superconducting loops interrupted at one side by superconducting nanowires which are joined together by a superconducting island. The phase difference developed at the edges of the nanowires by means of the magnetic flux threading the loops can collapse their Cooper condensates, leading to complete suppression of the Josephson energies. This mechanism allows to greatly reduce the leakage current when performing Cooper pair pumping by a pure magnetic pumping cycle without involving any gate modulation. The pumping capability of the JESP is studied through a master equation approach in the non-adiabatic case.