Neutral Collective Excitations in Striped Hall States

TL;DR

This paper investigates the neutral collective excitations in striped Hall states, revealing anisotropic spectra with multiple line nodes and similarities to liquid helium's phonon-roton spectrum, using the single mode approximation.

Contribution

It provides the first detailed analysis of the collective excitation spectrum in striped Hall states, highlighting anisotropic features and nodal structures.

Findings

Spectrum is anisotropic with multiple line nodes.

Resembles liquid helium spectrum with phonon and roton minima.

Spectrum varies across different Landau levels.

Abstract

In the striped Hall state, a magnetic translation in one direction is spontaneously broken to the discrete translation. The spectrum of the neutral collective excitation is obtained in the single mode approximation at half-filled third and fourth Landau levels. The spectrum is anisotropic and has a multiple line node structure. In one direction, the spectrum resembles the liquid Helium spectrum with the phonon and roton minimum.