Charge conversion of nearly free and impurity bound magneto-trions immersed in 2D electron or hole gas with optically tunable concentration
J. Jadczak, L. Bryja, J. Misiewicz, A. Wojs, M. Potemski, F. Liu, D. R. Yakovlev, M. Bayer, D. Reuter, A. D. Wieck, C. A. Nicoll, I. Farrer, D. A. Ritchie.
Journal of Physics Conference Series, 456, 012017, (2013)
We report collection of precise photoluminescence maps (emission intensity versus energy and magnetic field) of superior-quality two-dimensional hole gases. The maps reveal field evolution of both direct and cyclotron-assisted recombination lines attributed to various excitonic complexes, either moving nearly freely in the plane or bound to the acceptors placed inside or outside the quantum well. Under two-beam illumination (with photon energies below and above the band-gap in the barrier) we were able to control hole concentration (in the same well), and in particular to decrease it beyond the point of p- to n-type conversion. Our results demonstrate contrast between charge conversion of free and acceptor-bound positive trions resulting from the breaking of charge reflection symmetry by a fixed impurity.