Goldstone mode stochastization in quantum Hall ferromagnet

TL;DR

This paper investigates the unique relaxation mechanisms of Goldstone spin excitons in quantum Hall ferromagnets, revealing a distinct decay process associated with collective spin rotations in two-dimensional electron gases.

Contribution

It introduces the concept of Goldstone spin excitons in quantum Hall ferromagnets and analyzes their decay mechanisms, which differ from other collective spin states.

Findings

Goldstone spin excitons support a unique decay mechanism.

The system exhibits a coherent spin rotation mode.

Coulomb interactions influence spin relaxation processes.

Abstract

Experimental and theoretical studies of the coherent spin dynamics of two-dimensional GaAs/AlGaAs electron gas were performed. The system in the quantum Hall ferromagnet state exhibits a spin relaxation mechanism that is determined by many-particle Coulomb interactions. In addition to the spin exciton with changes in the spin quantum numbers of $\delta S\!=\!\delta S_z \!=\!-1$, the quantum Hall ferromagnet supports a Goldstone spin exciton that changes the spin quantum numbers to $\delta S\!=\!0$ and $\delta S_z\!=\!-1$, which corresponds to a coherent spin rotation of the entire electron system to a certain angle. The Goldstone spin exciton decays through a specific relaxation mechanism that is unlike any other collective spin state.