Cooper, Nigel

Monday April 11, 2011
Time: 11:00
Place: ETH Science City, HPF G 6
Host: Atac Imamoglu

Neutral Fermions and Skyrmions in the Moore-Read state at ν= 5/2

Nigel Cooper
University of Cambridge, U.K.

The fractional quantum Hall state at filling factor ν=5/2 is the subject of a great deal of experimental and theoretical interest at  present. This arises from the belief that it is likely described by the Moore-Read state -- an exotic phase of quantum matter, the charged excitations of which are predicted to exhibit non-abelian exchange statistics. I shall describe the different excitations of the Moore-Read state, making connections to its interpretation as a paired state of composite fermions. I shall present the results of our numerical studies of the excitations of the ν=5/2 state. Our results establish the properties a "neutral fermion" branch of excitations.They further predict the existence of "Skyrmions" (spin-unpolarized charged excitations). I shall explain how evidence for neutral fermions and Skyrmions can be sought in photoluminescence experiments.