Local current injection into mesoscopic superconductors for the manipulation of quantum states

TL;DR

This paper demonstrates how strategic local current injection in mesoscopic superconductors can control quantum states, enabling vortex splitting, state transitions, and switching, with potential applications in electronics and logic devices.

Contribution

It introduces a novel method of manipulating quantum states in mesoscopic superconductors through local current injection, supported by simulations and experimental measurements.

Findings

Current-driven splitting of multi-quanta vortices

Current-induced transitions between states with different angular momenta

Current-controlled switching between degenerate quantum states

Abstract

We perform strategic current injection in a small mesoscopic superconductor and control the (non)equilibrium quantum states in an applied homogeneous magnetic field. In doing so, we realize a current-driven splitting of multi-quanta vortices, current-induced transitions between states with different angular momenta, and current-controlled switching between otherwise degenerate quantum states. These fundamental phenomena form the basis for discussed electronic and logic applications, and are confirmed in both theoretical simulations and multiple-small-tunnel-junction transport measurements.