Photoluminescence hysteresis of the optically detected cyclotron-like resonance of a two-dimensional electron gas - art. no. 161306

A significant reduction of the two-dimensional electron gas (2DEG) density n(2D) in a modulation doped GaAs/AlGaAs quantum well is observed when the 2 D-electrons are heated by microwave (mw) irradiation at 1.8 K. A dependence of n(2D) on the effective electron temperature T-e leads to a remarkable h ysteresis of the optically detected dimensional magnetoplasma (cyclotronlik e) resonance, namely, to a bistability of the 2DEG-free hole photoluminesce nce (PL) spectrum as the magnetic field is scanned back and forth. The n(2D ) and T-e values for the nonequilibrium 2DEG are obtained from the PL spect rum analysis. The PL time-resolved study shows that n(2D) depends on the mw pulse duration and has a long recovery time similar to 10(-2) sec. This ph enomenon is attributed to an increased vertical transport of the warm elect rons out of the quantum well.