Vortex Physics in Confined Geometries

TL;DR

This paper develops a hydrodynamic theory for vortex liquids in confined geometries of cuprate superconductors, predicting critical behavior at the Bose glass transition and analyzing flux flow in various geometries.

Contribution

It generalizes vortex hydrodynamics to include currents and field gradients, deriving critical exponents for vortex viscosities and analyzing flux flow in confined geometries.

Findings

Shear viscosity diverges as |T - T_BG|^{-νz} with ν≈1 and z≈4.6.

Derived scaling behavior of ac resistivity near the transition.

Analyzed flux flow in channel and Corbino disk geometries.

Abstract

Patterned irradiation of cuprate superconductors with columnar defects allows a new generation of experiments which can probe the properties of vortex liquids by forcing them to flow in confined geometries. Such experiments can be used to distinguish experimentally between continuous disorder-driven glass transitions of vortex matter, such as the vortex glass or the Bose glass transition, and nonequilibrium polymer-like glass transitions driven by interaction and entanglement. For continuous glass transitions, an analysis of such experiments that combines an inhomogeneous scaling theory with the hydrodynamic description of viscous flow of vortex liquids can be used to infer the critical behavior. After generalizing vortex hydrodynamics to incorporate currents and field gradients both longitudinal and transverse to the applied field, the critical exponents for all six vortex liquid viscosities are obtained. In particular, the shear viscosity is predicted to diverge as $|T-T_{BG}|^{-\nu z}$ at the Bose glass transition, with $\nu\simeq 1$ and $z\simeq 4.6$ the dynamical critical exponent. The scaling behavior of the ac resistivity is also derived. As concrete examples of flux flow in confined geometries, flow in a channel and in the Corbino disk geometry are discussed in detail. Finally, the implications of scaling for the hydrodynamic description of transport in the dc flux transformer geometry are discussed.