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Excitons in motion: universal dependence of the magnetic moment on kinetic energy
Author(s) -
Kochereshko V. P.,
Smith L. C.,
Davies J. J.,
Cox R. T.,
Platonov A.,
Wolverson D.,
Boukari H.,
Mariette H.,
Cibert J.,
Wiater M.,
Wojtowicz T.,
Karczewski G.
Publication year - 2008
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200777614
Subject(s) - exciton , kinetic energy , rydberg formula , diamagnetism , zeeman effect , excited state , condensed matter physics , physics , atomic physics , chemistry , biexciton , magnetic field , quantum mechanics , ion , ionization
We have observed remarkable changes in the magnetic properties of excitons as they acquire kinetic energy. In particular, the Zeeman splittings and diamagnetic shifts of excitonic transitions when magnetic fields are applied along the growth direction of (001) wide quantum wells of CdTe, ZnSe, ZnTe and GaAs are found to to have a strong dependence on the translational wavevector K z . The behaviour of the Zee‐man splittings corresponds to enhancement of the magnetic moments of the excitons. This enhancement is particularly marked when their translational kinetic energy becomes comparable with the exciton Rydberg and can be described by what appears to be a universal function of K z . A model for the behaviour is outlined which involves motionally‐induced mixing between the 1S hydrogenic exciton ground state and excited nP states. The observations imply that there are significant changes in the structure of the exciton as its translational kinetic energy increases. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)