Josephson vortices and solitons inside pancake vortex lattice in layered superconductors

TL;DR

This paper investigates how Josephson vortices interact with pancake vortex lattices in layered superconductors, revealing their deformation, core evolution, and pinning effects across different anisotropies.

Contribution

It provides a detailed analysis of the structure and dynamics of Josephson vortices within pancake vortex lattices, highlighting the effects of anisotropy and vortex interactions.

Findings

Pancake vortices cause significant deformations in Josephson vortices.

The core structure of JVs evolves smoothly with anisotropy changes.

Pancake vortices strongly pin JVs, increasing viscous friction.

Abstract

In very anisotropic layered superconductors a tilted magnetic field generates crossing vortex lattices of pancake and Josephson vortices (JVs). We study the properties of an isolated JV in the lattice of pancake vortices. JV induces deformations in the pancake vortex crystal, which, in turn, substantially modify the JV structure. The phase field of the JV is composed of two types of phase deformations: the regular phase and vortex phase. The phase deformations with smaller stiffness dominate. The contribution from the vortex phase smoothly takes over with increasing magnetic field. We find that the structure of the cores experiences a smooth yet qualitative evolution with decrease of the anisotropy. At large anisotropies pancakes have only small deformations with respect to position of the ideal crystal while at smaller anisotropies the pancake stacks in the central row smoothly transfer between the neighboring lattice positions forming a solitonlike structure. We also find that even at high anisotropies pancake vortices strongly pin JVs and strongly increase their viscous friction.