Wigner solids of domain wall skyrmions

Kaifeng Yang,Katsumi Nagase,Hongwu Liu,Yoshiro Hirayama,Michael B Santos,Tetsuya D Mishima

doi:10.1038/s41467-021-26306-8

Abstract

Detection and characterization of a different type of topological excitations, namely the domain wall (DW) skyrmion, has received increasing attention because the DW is ubiquitous from condensed matter to particle physics and cosmology. Here we present experimental evidence for the DW skyrmion as the ground state stabilized by long-range Coulomb interactions in a quantum Hall ferromagnet. We develop an alternative approach using nonlocal resistance measurements together with a local NMR probe to measure the effect of low current-induced dynamic nuclear polarization and thus to characterize the DW under equilibrium conditions. The dependence of nuclear spin relaxation in the DW on temperature, filling factor, quasiparticle localization, and effective magnetic fields allows us to interpret this ground state and its possible phase transitions in terms of Wigner solids of the DW skyrmion. These results demonstrate the importance of studying the intrinsic properties of quantum states that has been largely overlooked.

Highlights

Detection and characterization of a different type of topological excitations, namely the domain wall (DW) skyrmion, has received increasing attention because the DW is ubiquitous from condensed matter to particle physics and cosmology
We demonstrate that the nonlocal measurement can be used to determine the intrinsic properties of bulk states
The Ising (easy-axis) QHF (IQHF) was identified by the resistively detected NMR (RDNMR) measurement of the Knight shift at ν = 215 and by the calculation based on the Hartree–Fock theory

Summary

Introduction

Detection and characterization of a different type of topological excitations, namely the domain wall (DW) skyrmion, has received increasing attention because the DW is ubiquitous from condensed matter to particle physics and cosmology. The nuclear spin relaxation (NSR) measurement, a generally accepted methodology for determining the low-frequency spin textures in the QH system (e.g., QH skyrmions)[16], shows an increase in magnetic fluctuations in the DW coupling to the nuclei with decreasing temperature and increasing localization.

Results

Conclusion