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Electro‐optic investigation of the Coherent Hall Effect in semiconductor superlattices
Author(s) -
Hummel Anne Beate,
Blöser Claudia,
Bauer Tobias,
Roskos Hartmut G.,
Kosevich Yuriy A.,
Köhler Klaus
Publication year - 2005
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.200460703
Subject(s) - terahertz radiation , magnetic field , electric field , physics , condensed matter physics , spectroscopy , oscillation (cell signaling) , superlattice , cyclotron , hall effect , electron , atomic physics , optics , chemistry , biochemistry , quantum mechanics
Abstract After the first observation of the Coherent Hall Effect in a GaAs/Al 0.3 Ga 0.7 As superlattice by means of THz‐emission spectroscopy, the dynamics of impulsively excited electron wavepackets in crossed electric and magnetic fields has now been investigated in more detail by reflective electro‐optic sampling (REOS). In agreement with the predictions of a semiclassical model, the experiments show the existence of two strictly separated regimes of charge‐carrier motion depending on the ratio E/B of applied electric and magnetic field. Both, the magneto‐Bloch regime for dominating electric field and the cyclotron‐like regime of motion for dominating magnetic field, exhibit a characteristic frequency dependence of the wavepacket oscillations on the external fields. The REOS measurements supplement our results achieved by THz‐emission spectroscopy by covering a much larger range of experimental parameters because REOS is not affected by absorption by the cryostat windows of our set‐up as is the THz radiation at frequencies above 2 THz, and the detection of high oscillation frequencies is possible. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)