35,570 research outputs found
Drift velocity of electrons in silicon at high electric fields from 4.2° to 300°K
The drift velocity of electrons in silicon at high electric fields is measured in the direction over the range of lattice temperatures from 4.2° to 300°K. It is established that in this range a limiting drift velocity exists. Its temperature dependence is measured. The samples used and the method of measurement are briefly described
Differential Step Response of Unipolar Space-Charge-Limited Current in Solids
The small signal step response of unipolar space‐charge‐limited current in solids is analyzed for planar structures and for media in which the drift velocity of the charge carriers is either proportional to the electric field (thermal charge carriers) or is independent of the electric field (hot charge carriers). Results are reported in analytical and graphical form. Their features are discussed in terms of the underlying physical phenomena, as well as in the perspective of experimental applications. Cylindrical and spherical structures are not accessible to closed‐form solutions by the approach
Left-right asymmetries and exotic vector-boson discovery in lepton-lepton colliders
By considering left-right (L-R) asymmetries we study the capabilities of
lepton colliders in searching for new exotic vector bosons. Specifically we
study the effect of a doubly charged bilepton boson and an extra neutral vector
boson appearing in a 3-3-1 model on the L-R asymmetries for the processes
, and and
show that these asymmetries are very sensitive to these new contributions and
that they are in fact powerful tools for discovery this sort of vector bosons.Comment: RevTeX, 22 pages, 12 eps figure
A supersymmetric 3-3-1 model
We build the complete supersymmetric version of a 3-3-1 gauge model using the
superfield formalism. We point out that a discrete symmetry, similar to the
R-symmetry in the minimal supersymmetric standard model, is possible to be
defined in this model. Hence we have both R-conserving and R-violating
possibilities. Analysis of the mass spectrum of the neutral real scalar fields
shown that in this model the lightest scalar Higgs has a mass upper limit, and
at the tree level it is 124.5 GeV for a given illustrative set of parameters.Comment: RevTex, extended and revised version, 20 pages, one eps figur
Supersymmetric 3-3-1 model with right-handed neutrinos
We consider the supersymmetric extension of the 3-3-1 model with right-handed
neutrinos. We study the mass spectra in the scalar and pseudoscalar sectors,
and for a given set of the input parameters, we find that the lightest scalar
in the model has a mass of 130 GeV and the lightest pseudoscalar has mass of 5
GeV. However, this pseudoscalar decouples from the at high energy scales
since it is almost a singlet under .Comment: Revtex4, 16 pages, no figure
Observation and analysis of Fano-like lineshapes in the Raman spectra of molecules adsorbed at metal interfaces
Surface enhanced Raman spectra from molecules (bipyridyl ethylene) adsorbed
on gold dumbells are observed to become increasingly asymmetric (Fano-like) at
higher incident light intensity. The electronic temperature (inferred from the
anti-Stokes (AS) electronic Raman signal increases at the same time while no
vibrational AS scattering is seen. These observations are analyzed by assuming
that the molecule-metal coupling contains an intensity dependent contribution
(resulting from light-induced charge transfer transitions as well as
renormalization of the molecule metal tunneling barrier). We find that
interference between vibrational and electronic inelastic scattering routes is
possible in the presence of strong enough electron-vibrational coupling and can
in principle lead to the observed Fano-like feature in the Raman scattering
profile. However the best fit to the observed results, including the dependence
on incident light intensity and the associated thermal response is obtained
from a model that disregards this coupling and accounts for the structure of
the continuous electronic component of the Raman scattering signal. The
temperatures inferred from the Raman signal are argued to be only of
qualitative value.Comment: 20 pages, 12 figure
Fermion Analogy for Layered Superconducting Films in Parallel Magnetic Field
The equivalence between the Lawrence-Doniach model for films of extreme
type-II layered superconductors and a generalization of the back-scattering
model for spin-1/2 electrons in one dimension is demonstrated. This fermion
analogy is then exploited to obtain an anomalous tail for
the parallel equilibrium magnetization of the minimal double layer case in the
limit of high parallel magnetic fields for temperatures in the
critical regime.Comment: 11 pages of plain TeX, 1 postscript figur
- …