Josephson vortex system in a flux-flow regime in electron doped high-Tc superconductor Nd(2-x)CexCuO4

TL;DR

This study investigates the flux-flow resistance behavior in an electron-doped high-Tc superconductor, revealing a periodic step structure linked to Josephson vortex dynamics and the superconductor's anisotropic penetration depths.

Contribution

It demonstrates the presence of a periodic step structure in flux-flow resistance related to Josephson vortices in Nd(2-x)CexCuO4, connecting vortex behavior to anisotropic penetration depths.

Findings

Periodic flux-flow resistance steps observed.

Vortex size determined by penetration depths.

Structure period related to flux quantum and penetration depths.

Abstract

For an epitaxial film of an electron-doped superconductor Nd(2-x)CexCuO4 (x=0.145), in a mixed state, a well-defined step structure is observed on the dependence of the c-axis flux-flow resistance on the magnetic field parralel to CuO2 layers. It is shown that in the region of a free flow of Josephson vortices, the structure is periodic with a period of deltaB~Phi0/(lambdaablambdac). It is essential that the magnetic penetration depths in the ab-plane (lambdaab) and along the c-axis (lambdac) determine the sizes of the Josephson vortices in the Lawrence-Doniach model for an anisotropic layered superconductor.