168,482 research outputs found
Modulation of the dephasing time for a magnetoplasma in a quantum well
We investigate the femtosecond kinetics of optically excited 2D
magneto-plasma. We calculate the femtosecond dephasing and relaxation kinetics
of the laser pulse excited magneto-plasma due to bare Coulomb potential
scattering, because screening is under these conditions of minor importance. By
taking into account four Landau subbands in both the conduction band and the
valence band, we are now able to extend our earlier study [Phys. Rev. B {\bf
58}, 1998,in print (see also cond-mat/9808073] to lower magnetic fields. We can
also fix the magnetic field and change the detuning to further investigate the
carrier density-dependence of the dephasing time. For both cases, we predict
strong modulation in the dephasing time.Comment: RevTex, 3 figures, to be published in Solid. Stat. Commu
Intense terahertz laser fields on a quantum dot with Rashba spin-orbit coupling
We investigate the effects of the intense terahertz laser field and the
spin-orbit coupling on single electron spin in a quantum dot. The laser field
and the spin-orbit coupling can strongly affect the electron density of states
and can excite a magnetic moment.
The direction of the magnetic moment depends on the symmetries of the system,
and its amplitude can be tuned by the strength and frequency of the laser field
as well as the spin-orbit coupling.Comment: 5 pages, 4 figures, to be published in J. Appl. Phy
Coulomb drag in double quantum wells with a perpendicular magnetic field
Momentum transfer due to electron-electron interaction (Coulomb drag) between
two quantum wells, separated by a distance , in the presence of a
perpendicular magnetic field, is studied at low temperatures. We find besides
the well known Shubnikov-de Haas oscillations, which also appear in the drag
effect, the momentum transfer is markedly enhanced by the magnetic field.Comment: 8 pages, Revtex, 4 Postscript figures are available upon request,
Accepted by Mod. Phys. Lett.
Smart windows: Thermal modelling and evaluation
Copyright @ 2014 The Authors. Published by Elsevier Ltd. This is an open access article shared under the CC BY license (http://creativecommons.org/licenses/by/3.0/).A numerical investigation of the performance of a multi paned smart window integrated with water-cooled high efficiency third generation GaAsP/InGaAs QWSC (∼32% efficiency) solar cells illuminated by two-axis tracking solar concentrators at 500× in the inter pane space is presented. Optimising system parameters such as optical concentration ratio and coolant (water) flow rate is essential in order to avoid degradation in system performance due to high cell temperatures and thermal stresses. Detailed modelling of the thermo-fluid characteristics of the smart windows system was undertaken using a finite volume CFD package. Results of this analysis which considered the conductive, convective and radiative heat exchange processes taking place in the interior of the smart window system as well as the heat exchange to the internal and external ambient environment are presented.Engineering and Physical Sciences Research Counci
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