Observation of two species of vortices in the anisotropic spin-triplet superconductor $Sr_2 Ru O_4$

TL;DR

This study visualizes two distinct vortex types in the anisotropic spin-triplet superconductor Sr₂RuO₄, revealing complex vortex arrangements and interactions using scanning micro SQUID microscopy.

Contribution

It provides the first direct imaging of vortex chains and crossing vortices in Sr₂RuO₄, highlighting anisotropic vortex behavior in a spin-triplet superconductor.

Findings

Vortex chains form when magnetic field is tilted in-plane.

In-plane vortices are decorated by crossing Abrikosov vortices.

Crossing vortices preferentially appear on in-plane vortices.

Abstract

Magnetic flux structures in single crystals of the layered spin triplet superconductor Sr$\_{2}$RuO$\_{4}$ are studied by scanning micro SQUID Force microscopy. Vortex chains appear as the applied field is tilted along the in-plane direction of the superconductor. The vortex chains align along the direction of the in-plane component of the applied magnetic field. The decoration of in-plane vortices by crossing Abrikosov vortices is observed: two vortex orientations are apparent simultaneously, one along the layers and the other perpendicular to the layers. The crossing vortices appear preferentially on the in-plane vortices.