Massive Spin Collective Mode in Quantum Hall Ferromagnet

TL;DR

This paper demonstrates that collective spin modes in quantum Hall ferromagnets, especially involving Skyrmions, can significantly influence nuclear spin relaxation, revealing a novel collective excitation with potential experimental implications.

Contribution

It introduces the concept of a massive spin collective mode associated with Skyrmions, highlighting its impact on nuclear spin relaxation in quantum Hall systems.

Findings

The collective spin rotation can be viewed as precession of the entire spin texture.

The effective moment of inertia becomes infinite as the g-factor approaches zero.

The low-lying spin excitation can enhance nuclear spin relaxation rates.

Abstract

It is shown that the collective spin rotation of a single Skyrmion in quantum Hall ferromagnet can be regarded as precession of the entire spin texture in the external magnetic field, with an effective moment of inertia which becomes infinite in the zero g-factor limit. This low-lying spin excitation may dramatically enhance the nuclear spin relaxation rate via the hyperfine interaction in the quantum well slightly away from filling factor equal one.