title: Optical probing of a fractionally charged quasihole in an incompressible liquid.
abstract: In photoluminescence spectroscopy of a low-mobility two-dimensional electron gas subjected to a quantizing magnetic field, we observe an anomaly around nu=1 / 3 at a very low temperature (0.1 K) and an intermediate electron density (0.9 x 10(11) cm(-2)). The anomaly is explained as due to perturbation of the incompressible liquid at the Laughlin state due to close proximity of a localized charged exciton which creates a fractionally charged quasihole in the liquid. The anomaly of approximately 2 meV can be destroyed by applying a small thermal energy of approximately 0.2 meV that is enough to close the quasihole energy gap.
authors.affiliation: Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, D-20355 Hamburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schüller
authors.forename: K-B
authors.initials: KB
authors.lastname: Broocks
authors.forename: P
authors.initials: P
authors.lastname: Schröter
authors.forename: Ch
authors.initials: Ch
authors.lastname: Heyn
authors.forename: D
authors.initials: D
authors.lastname: Heitmann
authors.forename: M
authors.initials: M
authors.lastname: Bichler
authors.forename: W
authors.initials: W
authors.lastname: Wegscheider
authors.forename: Tapash
authors.initials: T
authors.lastname: Chakraborty
authors.forename: V M
authors.initials: VM
authors.lastname: Apalkov