Berlin 2005 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 53: Transport im hohen Magnetfeld/Quanten-Hall-Effekt
HL 53.4: Vortrag
Dienstag, 8. März 2005, 15:45–16:00, TU P270
Parametric resonance of a two-dimensional electron gas under bichromatic irradiation — •Christian Joas1, Mikhail E. Raikh2, and Felix von Oppen1 — 1Fachbereich Physik, FU Berlin, Arnimallee 14, D-14195 Berlin — 2Department of Physics, University of Utah, Salt Lake City, UT 84112
In ultrahigh mobility 2D electron systems, even a weak nonparabolicity of the electron dispersion, by violating Kohn’s theorem, can have a drastic effect on dc magnetotransport under ac (microwave) drive. We study theoretically the manifestation of this effect in the dc response to the combined action of two driving ac-fields (bichromatic irradiation) within a simple classical model. Compared to the case of monochromatic irradiation, which is currently intensively studied both experimentally and theoretically, the presence of a second microwave source provides additional insight into the properties of an ac-driven 2D electron gas. We show[1] that nonparabolicity gives rise to new qualitative effects specific to bichromatic irradiation, namely parametric resonance and multistability within certain frequency ranges. For suitable microwave frequencies, this parametric instability can manifest itself in the dc properties of the system.
[1] C. Joas, M. E. Raikh, F. von Oppen, preprint cond-mat/0405443, to appear in Phys. Rev. B