Comment on "Moving Glass Phase of Driven Lattices"

TL;DR

This paper challenges previous elastic models of driven lattices by showing that displacements along the motion direction diverge, leading to a smectic phase with quasi-long-range order transversely and liquid-like behavior parallel to motion.

Contribution

It demonstrates the divergence of displacements along the motion direction, indicating a breakdown of elastic theory and proposing a moving smectic phase as a new state.

Findings

Displacements along the motion direction diverge at large scales.

Elastic model breaks down along the direction of motion.

Proposes a moving smectic phase with specific order properties.

Abstract

We consider a periodic lattice rapidly driven through a quenched random potential as a model of a moving Abrikosov lattice. In addition to the transverse phonon displacements $u_y$, we consider the displacements $u_x$ along the direction of motion, which were assumed to be small in earlier treatments. We show that these displacements are in fact divergent even on large length scales and therefore lead to a breakdown of the elastic model along the direction of motion. We propose that the resulting phase is a moving "smectic" with translational order that is quasi-long-range transverse and liquid-like parallel to the direction of motion.