Smectic vortex glass

TL;DR

This paper introduces the smectic vortex glass phase in type-II superconductors, characterized by unique anisotropic transport and positional order, arising from a transverse magnetic field interacting with columnar disorder.

Contribution

It identifies and characterizes a novel smectic vortex glass phase with distinct anisotropic properties and topological order in superconductors with columnar disorder.

Findings

SmVG exhibits infinite electrical anisotropy with resistive and dissipationless directions.

Long-range positional order with Bragg peaks along columnar defects.

Transition from Bragg glass to vortex glass due to point disorder at large scales.

Abstract

We show that in type-II superconductors a magnetic field applied transversely to correlated columnar disorder, drives a phase transition to a distinct "smectic" vortex glass (SmVG) state. SmVG is characterized by an infinitely anisotropic electrical transport, resistive (dissipationless) for current perpendicular to (along) columnar defects. Its positional order is also quite unusual, long-ranged with true Bragg peaks along columnar defects and logarithmically rough vortex lattice distortions with quasi-Bragg peaks transverse to columnar defects. For low temperatures and sufficiently weak columnar-only disorder, SmVG is a true topologically-ordered "Bragg glass", characterized by a vanishing dislocation density. At sufficiently long scales the residual ever-present point disorder converts this state to a more standard, but highly anisotropic vortex glass.