Condensed Matter and Materials Physics(DCMMP)
Physique de la matière condensée et des matériaux (DPMCM)
Patash CHAKRABORTY
University of Manitoba
How to Probe a Fractionally-Charged Quasihole?
A curious anomalous dispersion of charged excitons in photoluminescence experiments on a two-dimensional electron gas subjected to a quantizing magnetic field at and around 1/3 filling of the lowest Landau level was observed experimentally. The anomaly exists only at a very low temperature and an intermediate electron densityi of the electron gas. We explained the anomaly as due to a perturbation of the incompressible liquid at the 1/3 filling factor, induced by the close proximity of a localized charged exciton which creates a fractionally-charged quasihole in the liquid. The intriguing experimentally observed puzzle that the anomaly can be destroyed by applying a very small thermal energy is thereby resolved, as this energy is found to be enough to close the quasihole energy gap. This work is the first ever probe of the quasihole gap in a quantum Hall system.