23 research outputs found
Observation of linear-polarization-sensitivity in the microwave-radiation-induced magnetoresistance oscillations
In the quasi two-dimensional GaAs/AlGaAs system, we investigate the effect of
rotating \textit{in-situ} the electric field of linearly polarized microwaves
relative to the current, on the microwave-radiation-induced magneto-resistance
oscillations. We find that the frequency and the phase of the photo-excited
magneto-resistance oscillations are insensitive to the polarization. On the
other hand, the amplitudes of the magnetoresistance oscillations are remarkably
responsive to the relative orientation between the microwave antenna and the
current-axis in the specimen. The results suggest a striking
linear-polarization-sensitivity in the radiation-induced magnetoresistance
oscillations.Comment: 4 figures, 5 page
Microwave-induced electron heating in the regime of radiation-induced magnetoresistance oscillations
We examine the influence of microwave photoexcitation on the amplitude of
Shubnikov-de Haas (SdH) oscillations in a two dimensional GaAs/AlGaAs electron
system in a regime where the cyclotron frequency, , and the
microwave angular frequency, , satisfy . A SdH lineshape analysis indicates that increasing the incident
microwave power has a weak effect on the amplitude of the SdH oscillations, in
comparison to the influence of modest temperature changes on the dark-specimen
SdH effect. The results indicate negligible electron heating under modest
microwave photoexcitation, in good agreement with theoretical predictions.Comment: 5 pages, 4 color figure
Quantum magneto-optics of graphite family
The optical conductivity of graphene, bilayer graphene, and graphite in
quantizing magnetic fields is studied. Both dynamical conductivities,
longitudinal and Hall's, are analytically evaluated. The conductivity peaks are
explained in terms of electron transitions. We have shown that trigonal warping
can be considered within the perturbation theory for strong magnetic fields
larger than 1 T and in the semiclassical approach for weak fields when the
Fermi energy is much larger than the cyclotron frequency. The main optical
transitions obey the selection rule with \Deltan = 1 for the Landau number n,
however the \Deltan = 2 transitions due to the trigonal warping are also
possible. The Faraday/Kerr rotation and light transmission/reflection in the
quantizing magnetic fields are calculated. Parameters of the
Slonczewski-Weiss-McClure model are used in the fit taking into account the
previous dHvA measurements and correcting some of them for the case of strong
magnetic fields.Comment: 28 pages, 12 figures. arXiv admin note: text overlap with
arXiv:1106.340
References
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