Dynamic interactions between pancake vortex stacks and Josephson vortices in Bi2Sr2CaCu2O8 single crystals: relaxation and ratchets

TL;DR

This study investigates the dynamic interactions between Josephson and pancake vortices in Bi2Sr2CaCu2O8 crystals, revealing relaxation towards equilibrium and potential for flux ratchet applications through measured forces.

Contribution

It provides detailed experimental insights into vortex interactions and demonstrates the existence of forces that could enable flux ratchet devices.

Findings

System relaxes towards equilibrium under magnetic pulses

Detection of forces driving system away from equilibrium

Potential for flux ratchet device applications

Abstract

We present a detailed study of the dynamic interactions between Josephson vortices and stacks of pancake vortices in a Bi2Sr2CaCu2O8 single crystal, obtained by measuring the effect of applied inplane magnetic field pulses on the c-axis magnetisation. The predominant interaction is to relax the system towards equilibrium. However, using a highly sensitive AC technique we are able to measure also the forces acting to drive the system away from equilibrium, consistent with the existence of dragging interactions between the Josephson and pancake systems. Such forces were discussed recently as the basis of possible flux ratchet devices.