Suris tetrons: possible spectroscopic evidence for four-particle optical excitations of a two-dimensional electron gas.
The excitations of a two-dimensional electron gas in quantum wells with intermediate carrier density (ne∼1011  cm-2), i.e., between the exciton-trion and the Fermi-sea range, are so far poorly understood. We report on an approach to bridge this gap by a magnetophotoluminescence study of modulation-doped (Cd,Mn)Te quantum well structures. Employing their enhanced spin splitting, we analyzed the characteristic magnetic-field behavior of the individual photoluminescence features. Based on these results and earlier findings by other authors, we present a new approach for understanding the optical transitions at intermediate densities in terms of four-particle excitations, the Suris tetrons, which were up to now only predicted theoretically. All characteristic photoluminescence features are attributed to emission from these quasiparticles when attaining different final states.
A. F. Ioffe Physico-Technical Institute of RAS, 194021 Saint Petersburg, Russia and Spin Optics Laboratory, Saint Petersburg State University, 198504 Saint Petersburg, Russia.
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Koudinov
Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg, Germany.
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Kehl
A. F. Ioffe Physico-Technical Institute of RAS, 194021 Saint Petersburg, Russia.
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Rodina
Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg, Germany.
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Geurts
Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom.
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Wolverson
Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland.
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Karczewski