The absorption spectrum around nu=1: evidence for a small size Skyrmion

TL;DR

This study investigates the absorption spectrum of a 2D electron system near filling factor 1, revealing the presence of small Skyrmions through spectral analysis of bound electron-hole complexes.

Contribution

It provides experimental evidence for small-sized Skyrmions in a 2DES near nu=1 using absorption spectrum measurements.

Findings

Identification of bound electron-hole complexes in the spectrum

Oscillator strength as a probe of spatial correlations

Evidence for small Skyrmions near nu=1

Abstract

We measure the absorption spectrum of a two-dimensional electron system (2DES) in a GaAs quantum well in the presence of a perpendicular magnetic field. We focus on the absorption spectrum into the lowest Landau Level around nu=1. We find that the spectrum consists of bound electron-hole complexes, trion and exciton like. We show that their oscillator strength is a powerful probe of the 2DES spatial correlations. We find that near nu=1 the 2DES ground state consists of Skyrmions of small size (a few magnetic lengths).