2000/01/21 by Arkadiusz Wojs, Arkadiusz Wójs, John J. Quinn +2 · 6 citations
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.62.4630
published as Phys. Rev. B, 62, 4630 (2000) · 8 pages, 5 figures, submitted to Phys.Rev.B
arxiv created 2000/01/21 · openalex publication_date 2000/08/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
A theory of charged excitons X^\ensuremath- in a dilute two-dimensional (2D) electron gas in a high-magnetic field is presented. In contrast to previous calculations, three bound X^\ensuremath- states (one singlet and two triplets) are found in a narrow and symmetric GaAs quantum well. The singlet and a ``bright'' triplet are the two optically active states observed in experiments. The bright triplet has the binding energy of about 1 meV, smaller than the singlet and a ``dark'' triplet. The interaction of bound X^\ensuremath-'s with a dilute 2D electron gas is investigated using exact diagonalization techniques. It is found that the short-range character of the e--X^\ensuremath- interactions effectively isolates bound X^\ensuremath- states from a dilute e--h plasma. This results in the insensitivity of the photoluminescence spectrum to the filling factor \ensuremathν, and a rapid decrease of the oscillator strength of the dark triplet X^\ensuremath- as a function of \ensuremathν^\ensuremath-1.