Soft Spin Wave Near nu=1: Evidence for a Magnetic Instability in Skyrmion Systems

TL;DR

This study investigates the magnetic properties of a two-dimensional electron gas near filling factor 1, revealing a soft spin wave indicative of a magnetic instability possibly related to Skyrme crystal formation.

Contribution

It provides experimental evidence of a magnetic instability and soft spin wave behavior near ν=1, suggesting a transition to a new magnetic order in Skyrmion systems.

Findings

Collapse of ferromagnetic spin wave away from ν=1

Emergence of a low-energy spin wave below the Zeeman gap

Softening of the spin wave indicating magnetic instability

Abstract

The ground state of the two dimensional electron gas near $\nu$=1 is investigated by inelastic light scattering measurements carried down to very low temperatures. Away from $\nu$=1, the ferromagnetic spin wave collapses and a new low-energy spin wave emerges below the Zeeman gap. The emergent spin wave shows soft behavior as its energy increases with temperature and reaches the Zeeman energy for temperatures above 2 K. The observed softening indicates an instability of the two dimensional electron gas towards a magnetic order that breaks spin rotational symmetry. We discuss our findings in light of the possible existence of a Skyrme crystal.