Absorption spectrum around nu=1: evidence for a small-size Skyrmion

Phys Rev Lett. 2004 Aug 27;93(9):096802. doi: 10.1103/PhysRevLett.93.096802. Epub 2004 Aug 26.

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, trionlike and excitonlike. 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).