Observation of retardation effects in the spectrum of two-dimensional plasmons.
Retardation effects, theoretically predicted more than 35 years ago, are observed in the spectrum of two-dimensional plasmons in high-electron-mobility GaAs/AlGaAs quantum wells. In zero magnetic field, a strong reduction of the resonant plasma frequency is observed due to the hybridization of the plasma and light modes. In a perpendicular magnetic field B, hybrid cyclotron-plasmon modes appear with a very unusual dependence of the frequency on B field. Experimental results are in excellent agreement with the theory.
Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
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Kukushkin
J H
JH
Smet
S A
SA
Mikhailov
D V
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Kulakovskii
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K
von Klitzing
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Wegscheider