Spin currents and spin textures are observed in a coherent gas of indirect excitons. Applied magnetic fields bend the spin current trajectories and transform patterns of linear polarization from helical to spiral and patterns of circular polarization from four-leaf to bell-like-with-inversion.
We realized a potential energy gradient - a ramp - for indirect excitons using a shaped electrode at constant voltage. We studied transport of indirect excitons along the ramp and observed that the exciton transport distance increases with increasing density and temperature.
We report on the study of indirect excitons in moving lattices - conveyers created by a set of AC voltages applied to the electrodes on the sample surface. The wavelength of this moving lattice is set by the electrode periodicity, the amplitude is co
ntrolled by the applied voltage, and the velocity is controlled by the AC frequency. We observed the dynamical localization-delocalization transition for excitons in the conveyers and measured its dependence on the exciton density and conveyer amplitude and velocity. We considered a model for exciton transport via conveyers. The theoretical simulations are in agreement with the experimental data.
Spin transport of indirect excitons in GaAs/AlGaAs coupled quantum wells was observed by measuring the spatially resolved circular polarization of exciton emission. Exciton spin transport over several microns originates from a long spin relaxation time and long lifetime of indirect excitons.
