Su, B. and Schröter, Patrick and Heitmann, Detlef and Perakis, Ilias. E. and Wegscheider, Werner and Schüller, Christian
Ultrafast spectroscopy of the quantum Hall ferromagnet.
Physica E Low-dimensional Systems and Nanostructures 34 (1-2), pp. 381-384.
We report ultrafast spectroscopy experiments at the ν=1 quantum Hall state of a high-mobility two-dimensional electron system in a GaAs single quantum well. By spectrally resolved four-wave-mixing measurements we investigate the coherent dynamics of photo-excited electron–hole pairs and find extraordinarily long decoherence times for electrons in the upper spin level around ν=1. We interpret the observed slower decrease of the dephasing time for ν>1, as compared to ν<1, as a fingerprint of Skyrmion formation dynamics.