Commensurate and Incommensurate Vortex States Confined in Mesoscopic Triangles of Weak Pinning Superconducting Thin Films

TL;DR

This paper presents direct imaging of vortex states in mesoscopic triangular superconducting films, revealing both commensurate and incommensurate configurations, and analyzes their stability and symmetry.

Contribution

It provides the first direct visualization and comparison of vortex states in triangular geometries, including metastable incommensurate states, in weak pinning superconducting films.

Findings

Observation of both commensurate and incommensurate vortex states

Analysis of vortex configuration stability against shape deformations

Identification of metastable vortex configurations

Abstract

We report on the direct observation of vortex states confined in equilateral and isosceles triangular dots of weak pinning amorphous superconducting thin films with a scanning superconducting quantum interference device microscope. The observed images illustrate not only pieces of a triangular vortex lattice as commensurate vortex states, but also incommensurate vortex states including metastable ones. We comparatively analyze vortex configurations found in different sample geometries and discuss the symmetry and stability of commensurate and incommensurate vortex configurations against deformations of the sample shape.