Abstract
Gunnar Möller (University of Cambridge, United Kingdom)
Skyrmions in the ν=5/2 state
We study spinful excitations in the Moore-Read state. Energetics of the skyrmion based on a spin-wave picture support the existence of skyrmion excitations in the plateau below filling fraction ν=5/2. This prediction is then tested numerically. We construct trial skyrmion wavefunctions for general FQHE states, and obtain significant overlaps for the predicted skyrmions of ν=5/2. The case of $nu;=5/2. is particularly interesting as skyrmions have twice the charge of quasiparticles (qp's). As the spin polarization of the system is tuned from full to none, we observe a transition between qp- and skyrmion-like behaviour of the excitation spectrum that can be interpreted as binding of qp's. Our ED results confirm that skyrmion states are energetically competitive with quasiparticles at low Zeeman coupling. Disorder and large density of quasiparticles are discussed as further mechanisms for depolarization.