2,131 research outputs found
Non-linear conductivity and quantum interference in disordered metals
We report on a novel non-linear electric field effect in the conductivity of
disordered conductors. We find that an electric field gives rise to dephasing
in the particle-hole channel, which depresses the interference effects due to
disorder and interaction and leads to a non-linear conductivity. This
non-linear effect introduces a field dependent temperature scale and
provides a microscopic mechanism for electric field scaling at the
metal-insulator transition. We also study the magnetic field dependence of the
non-linear conductivity and suggest possible ways to experimentally verify our
predictions. These effects offer a new probe to test the role of quantum
interference at the metal-insulator transition in disordered conductors.Comment: 5 pages, 3 figure
Current-induced spin polarization and the spin Hall effect: a quasiclassical approach
The quasiclassical Green function formalism is used to describe charge and
spin dynamics in the presence of spin-orbit coupling. We review the results
obtained for the spin Hall effect on restricted geometries. The role of
boundaries is discussed in the framework of spin diffusion equations.Comment: 10 pages, 5 figures, Submitted to Solid State Communications Special
Issue on "Fundamental Phenomena in Low Dimensional Electron Systems". Special
Issue Editors: Marco Polini, Michele Governale, Hermann Grabert, Vittorio
Pellegrini, and Mario Tos
High luminosity interaction region design for collisions with detector solenoid
An innovatory interaction region has been recently conceived and realized on
the Frascati DA{\Phi}NE lepton collider. The concept of tight focusing and
small crossing angle adopted until now to achieve high luminosity in multibunch
collisions has evolved towards enhanced beam focusing at the interaction point
with large horizontal crossing angle, thanks to a new compensation mechanism
for the beam-beam resonances. The novel configuration has been tested with a
small detector without solenoidal field yielding a remarkable improvement in
terms of peak as well as integrated luminosity. The high luminosity interaction
region has now been modified to host a large detector with a strong solenoidal
field which significantly perturbs the beam optics introducing new design
challenges in terms of interaction region optics design, beam transverse
coupling control and beam stay clear requirementsComment: 3 pages, 4 figures, presented to the IPAC10 conferenc
Spin polarizations and spin Hall currents in a two-dimensional electron gas with magnetic impurities
We consider a two-dimensional electron gas in the presence of Rashba
spin-orbit coupling, and study the effects of magnetic s-wave impurities and
long-range non-magnetic disorder on the spin-charge dynamics of the system. We
focus on voltage induced spin polarizations and their relation to spin Hall
currents. Our results are obtained using the quasiclassical Green function
technique, and hold in the full range of the disorder parameter .Comment: 5 pages, 2 figures. References added, minor stylistic modification
Inverse Spin Hall Effect and Anomalous Hall Effect in a Two-Dimensional Electron Gas
We study the coupled dynamics of spin and charge currents in a
two-dimensional electron gas in the transport diffusive regime. For systems
with inversion symmetry there are established relations between the spin Hall
effect, the anomalous Hall effect and the inverse spin Hall effect. However, in
two-dimensional electron gases of semiconductors like GaAs, inversion symmetry
is broken so that the standard arguments do not apply. We demonstrate that in
the presence of a Rashba type of spin-orbit coupling (broken structural
inversion symmetry) the anomalous Hall effect, the spin Hall and inverse spin
Hall effect are substantially different effects. Furthermore we discuss the
inverse spin Hall effect for a two-dimensional electron gas with Rashba and
Dresselhaus spin-orbit coupling; our results agree with a recent experiment.Comment: 5 page
Evaluating the Factor Structure of the Emotion Dysregulation Scale-Short (EDS-s): A Preliminary Study
Emotion dysregulation (ED) can be considered a psychopathological transdiagnostic dimension, the presence of which should be reliably screened in clinical settings. The aim of the current study was to validate the Italian version of the Emotion Dysregulation Scale-short (EDS-s), a brief self-report tool assessing emotion dysregulation, in a non-clinical sample of 1087 adults (768 women and 319 men). We also assessed its convergent validity with scales measuring binge eating and general psychopathology. Structural equation modeling suggested the fit of a one-factor model refined with correlations between the errors of three pairs of items (χ2 = 255.56, df = 51, p < 0.001, RMSEA = 0.08, CFI = 0.94, TLI = 0.93, SRMR = 0.04). The EDS-s demonstrated satisfactory internal consistency (ordinal alpha = 0.94). Moreover, EDS-s scores partly explained the variance of both binge eating (0.35, p < 0.001) and general psychopathology (0.60, p < 0.001). In conclusion, the EDS-s can be considered to be a reliable and valid measure of ED
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