Observation of pinning mode of stripe phases of 2D systems in high Landau levels

TL;DR

This paper reports the observation of a resonance in the radio-frequency conductivity of stripe phases in high Landau levels, interpreted as a pinning mode, revealing anisotropic collective behavior.

Contribution

It provides the first experimental evidence of a pinning mode in stripe phases of 2D electron systems at high Landau levels.

Findings

Resonance observed in hard direction conductivity

No resonance detected in easy direction

Resonance attributed to pinning mode of stripe phase

Abstract

We study the radio-frequency diagonal conductivities of the anisotropic stripe phases of higher Landau levels near half integer fillings. In the hard direction, in which larger dc resistivity occurs, the spectrum exhibits a striking resonance, while in the orthogonal, easy direction, no resonance is discernable. The resonance is interpreted as a pinning mode of the stripe phase.