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Stability of trions in strongly spin-polarized two-dimensional electron gases

S. A. Crooker·E. Johnston-Halperin·D. D. Awschalom·R. Knobel·N. Samarth
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Abstract

Low-temperature magneto-photoluminescence studies of negatively charged excitons (X- trions) are reported for n-type modulation-doped ZnSe/Zn(Cd,Mn)Se quantum wells over a wide range of Fermi energy and spin-splitting. The magnetic composition is chosen such that these magnetic two-dimensional electron gases (2DEGs) are highly spin-polarized even at low magnetic fields, throughout the entire range of electron densities studied (5e10 to 6.5e11 cm^-2). This spin polarization has a pronounced effect on the formation and energy of X-, with the striking result that the trion ionization energy (the energy separating X- from the neutral exciton) follows the temperature- and magnetic field-tunable Fermi energy. The large Zeeman energy destabilizes X- at the nu=1 quantum limit, beyond which a new PL peak appears and persists to 60 Tesla, suggesting the formation of spin-triplet charged excitons.

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S. A. Crooker, E. Johnston-Halperin, D. D. Awschalom, R. Knobel, N. Samarth. 2000-01-27. Stability of trions in strongly spin-polarized two-dimensional electron gases. https://doi.org/10.1103/physrevb.61.r16307

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