1,373 research outputs found
Magnetoplasmons excitations in graphene for filling factors
In the frame of the Hartree-Fock approximation, the dispersion of
magnetoplasmons in Graphene is derived for all types of transitions for filling
factors . The optical conductivity components of the magnetoplasmon
curves are calculated. It is shown that the electron-electron interactions lead
to a strong re-normalization of the apparent Fermi velocity of Graphene which
is different for different types of transitions.Comment: 15 pages, 7 figure
Evidence for magnetoplasmon character of the cyclotron resonance response of a two-dimensional electron gas
Experimental results on the absolute magneto-transmission of a series of high
density, high mobility GaAs quantum wells are compared with the predictions of
a recent magnetoplasmon theory for values of the filling factor above 2. We
show that the magnetoplasmon picture can explain the non-linear features
observed in the magnetic field evolution of the cyclotron resonance energies
and of the absorption oscillator strength. This provides experimental evidence
that inter Landau level excitations probed by infrared spectroscopy need to be
considered as many body excitations in terms of magnetoplasmons: this is
especially true when interpreting the oscillator strengths of the cyclotron
transitions
Spin-Orbit Coupling and Tunneling Current in a Parabolic Quantum Dot
We propose a novel approach to explore the properties of a quantum dot in the
presence of the spin-orbit interaction and in a tilted magnetic field. The
spin-orbit coupling within the quantum dot manifest itself as anti-crossing of
the energy levels when the tilt angle is varied. The anti-crossing gap has a
non-monotonic dependence on the magnitude of the magnetic field and exhibits a
peak at some finite values of the magnetic field. From the dependence of the
tunneling current through the quantum dot on the bias voltage and the tilt
angle, the anti-crossing gap and most importantly the spin-orbit strength can
be uniquely determined
Two exact properties of the perturbative expansion for the two-dimensional electron liquid with Rashba or Dresselhaus spin-orbit coupling
We have identified two useful exact properties of the perturbative expansion
for the case of a two-dimensional electron liquid with Rashba or Dresselhaus
spin-orbit interaction and in the absence of magnetic field. The results allow
us to draw interesting conclusions regarding the dependence of the exchange and
correlation energy and of the quasiparticle properties on the strength of the
spin-orbit coupling which are valid to all orders in the electron-electron
interaction.Comment: 6 pages, 1 figur
Anomalous Hall effect in a two-dimensional electron gas with spin-orbit interaction
We discuss the mechanism of anomalous Hall effect related to the contribution
of electron states below the Fermi surface (induced by the Berry phase in
momentum space). Our main calculations are made within a model of
two-dimensional electron gas with spin-orbit interaction of the Rashba type,
taking into account the scattering from impurities. We demonstrate that such an
"intrinsic" mechanism can dominate but there is a competition with the
impurity-scattering mechanism, related to the contribution of states in the
vicinity of Fermi surface. We also show that the contribution to the Hall
conductivity from electron states close to the Fermi surface has the intrinsic
properties as well.Comment: 9 pages, 6 figure
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