Evidence for Skyrmions and Single Spin Flips in the Integer Quantized Hall Effect

TL;DR

This study uses tilted-field magneto-transport measurements to investigate the spin structure of excitations in the integer quantum Hall effect, providing evidence for Skyrmions at filling factor 1 and simpler excitations at higher odd fillings.

Contribution

It offers experimental evidence for Skyrmions as lowest-energy excitations at ν=1 and distinguishes excitation types at higher odd-integer fillings.

Findings

Up to 7 electron spin flips at ν=1

Only a single spin flip at ν=3 and 5

Supports Skyrmions as lowest-lying excitations at ν=1

Abstract

We have employed tilted-field magneto-transport measurements of the energy gap for the odd-integer quantized Hall states at Landau level filling factors $\nu = 1$,3 and 5 to determine the spin of thermally excited quasielectron-quasihole pairs. At $\nu = 1$ our data show that as many as 7 electron spin flips accompany such excitations, while at $\nu =3$ and 5 apparently only a single spin flips. These results lend support to the recent suggestions that "Skyrmionic" quasiparticles are the lowest-lying charged excitations of the fully-polarized $\nu = 1$ quantum Hall fluid but are not at the higher odd-integer fillings.