Attractive interaction between superconducting vortices in tilted magnetic fields

TL;DR

This study uses magnetic force microscopy to observe and manipulate intertwined Josephson and Abrikosov vortices in a layered high-Tc superconductor under tilted magnetic fields, revealing their mutual interactions and manipulability.

Contribution

It provides direct experimental evidence of vortex interactions in tilted fields and demonstrates the potential for manipulating vortex lattices in layered superconductors.

Findings

Josephson vortices can be brought on top of Abrikosov vortices.

Intertwined vortex lattices are intrinsically easy to manipulate.

Magnetic force microscopy enables direct observation of vortex dynamics.

Abstract

Many practical applications of high T$_c$ superconductors involve layered materials and magnetic fields applied on an arbitrary direction with respect to the layers. When the anisotropy is very large, Cooper pair currents can circulate either within or perpendicular to the layers. Thus, tilted magnetic fields lead to intertwined lattices of Josephson and Abrikosov vortices, with quantized circulation across and within layers, respectively. Transport in such intertwined lattices has been studied in detail, but direct observation and manipulation of vortices remains challenging. Here we present magnetic force microscopy experiments in tilted magnetic fields in the extremely quasi-two dimensional superconductor $Bi_{2}Sr_{2}CaCu_{2}O_{8}$. We trigger Abrikosov vortex motion in between Josephson vortices, and find that Josephson vortices in different layers can be brought on top of each other. Our measurements suggest that intertwined lattices in tilted magnetic fields can be intrinsically easy to manipulate thanks to the mutual interaction between Abrikosov and Josephson vortices.