Topological transitions in superconductor nanomembranes in a magnetic field with submicron inhomogeneity under a strong transport current

TL;DR

This paper investigates topological transitions and phase-slip phenomena in superconductor nanomembranes under strong currents and magnetic fields with submicron inhomogeneity, revealing complex vortex dynamics and their effects on electrical characteristics.

Contribution

It introduces a detailed analysis of topological transitions involving weak superconducting current loops and vortex-antivortex dynamics in inhomogeneous superconductor nanostructures.

Findings

Identification of two new weak superconducting current loops during topological transition.

Observation of rapid vortex-antivortex pair dynamics with distinct lifetimes.

Voltage-magnetic field characteristics influenced by phase-slip regimes in nanoarchitectures.

Abstract

Under a strong transport current, the induced voltage in superconductor nanomembranes in a magnetic field with submicron inhomogeneity shows a pulse on a certain interval of the magnetic field. It is a manifestation of a wide phase-slip domain. The topological transition accompanying the phase-slip effect consists in the occurrence of two new loops of weak superconducting currents connecting two regions of superconducting screening currents, which are disconnected in case of vortex-chain dynamics. In the middle of the phase-slip domain, rapid dynamics of the superconducting order parameter consists in decoupling of a spontaneously nucleated vortex-antivortex pair, subsequent motion of a vortex and an antivortex in the opposite directions followed by their annihilation with an antivortex and a vortex from the adjacent pairs. The submicron-scale inhomogeneity of the magnetic field can be achieved through a direct patterning of the magnetic field applied to a planar membrane or using advanced nanostructuring, such as roll-up technology, focused ion-beam deposition or coating carbon nanotubes by superconducting materials. If the applied magnetic field is orthogonal to the axis of a microtube, which carries transport current in the azimuthal direction, the phase-slip regime is characterized by the vortex-antivortex lifetime of 10E-15 s versus 10E-12 s for disconnected vortex dynamics in the half-tubes. The phase-slip dynamics determines the voltage-magnetic field and voltage-current characteristics in nanoarchitectures with multiple disconnected loops of superconducting screening currents.