630 research outputs found
Manifestation of spin-orbit interaction in tunneling between 2D electron layers
An influence of spin-orbit interaction on the tunneling between two 2D
electron layers is considered. Particular attention is addressed to the
relation between the contribution of Rashba and Dresselhaus types. It is shown
that without scattering of the electrons, the tunneling conductance can either
exhibit resonances at certain voltage values or be substantially suppressed
over the whole voltage range. The dependence of the conductance on voltage
turns out to be very sensitive to the relation between Rashba and Dresselhaus
contributions even in the absence of magnetic field. The elastic scattering
broadens the resonances in the first case and restores the conductance to a
larger magnitude in the latter one. These effects open possibility to determine
the parameters of spin-orbit interaction and electrons scattering time in
tunneling experiments with no necessity of external magnetic field
Configuration interaction in delta-doped heterostructures
We analyze the tunnel coupling between an impurity state located in a
-layer and the 2D delocalized states in the quantum well (QW) located
at a few nanometers from the -- layer. The problem is formulated in
terms of Anderson-Fano model as configuration interaction between the carrier
bound state at the impurity and the continuum of delocalized states in the QW.
An effect of this interaction on the interband optical transitions in the QW is
analyzed. The results are discussed regarding the series of experiments on the
GaAs structures with a -Mn layer.Comment: arXiv admin note: substantial text overlap with arXiv:1111.089
Effect of intersubband scattering on weak localization in 2D systems
The theory of weak localization is generalized for multilevel 2D systems
taking into account intersubband scattering. It is shown that weak intersubband
scattering which is negligible in a classical transport, affects strongly the
weak-localization correction to conductivity. The anomalous magnetoresistance
is calculated in the whole range of classically low magnetic fields. This
correction to conductivity is shown to depend strongly on the ratios of
occupied level concentrations. It is demonstrated that at relatively low
population of the excited subband, it is necessary to use the present theory
because the high-field limit asimptotics is shown to be achieved only in
classical magnetic fields.Comment: 18 pages, 4 figures. Accepted to Phys. Rev. B 6
Spatial structure of Mn-Mn acceptor pairs in GaAs
The local density of states of Mn-Mn pairs in GaAs is mapped with
cross-sectional scanning tunneling microscopy and compared with theoretical
calculations based on envelope-function and tight-binding models. These
measurements and calculations show that the crosslike shape of the Mn-acceptor
wavefunction in GaAs persists even at very short Mn-Mn spatial separations. The
resilience of the Mn-acceptor wave-function to high doping levels suggests that
ferromagnetism in GaMnAs is strongly influenced by impurity-band formation. The
envelope-function and tight-binding models predict similarly anisotropic
overlaps of the Mn wave-functions for Mn-Mn pairs. This anisotropy implies
differing Curie temperatures for Mn -doped layers grown on differently
oriented substrates.Comment: 4 pages, 4 figure
Analysis of plasmonic nanoparticles applications and their influence on scattered electric field
It is known that plasmon-induced photocatalytic reaction can may occur due to the excitation of electrons on the surface of plasmonic nanoparticles (NP) but there are also other ways due to which a «hot electron» transfer reaction and a photocatalytic reaction are possible. Nowadays, there are several reports that highlight possible methods of various applications of photocatalytic reactions. The first aim of this report is to analyze excited researches about different mechanisms of photocatalysis and their implications in medicine to find out new approach in cancer treatment available for every person in society, and diagnostics. The second aim is to show nanosphere 3D simulation results of enhancement and electric field dependents of irradiation light wavelength, and size of NP. Also, this review is highlighting some investigation methods of plasmon-induced photocatalytic reaction at the micro and nanoscal
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