Browsing Articles  Science and Technology by Issue Date
Now showing items 120 of 720

Bifurcation and total stability
(C E D A M, 1984) 
Degeneracy in the ensemble Monte Carlo method for highfield transport in semiconductors
(1985)An algorithm to include the Pauli exclusion principle in the Ensemble Monte Carlo method is presented. The results indicate that significant changes in the transport properties of GaAs have to be expected when degenerate ... 
A generalization of Kubo formalism for hotelectron transport
(PERGAMONELSEVIER SCIENCE LTD, 1988)We present a generalization of Kubo formalism to the case of far from equilibrium conditions, as obtained in semiconductors high field transport. Analytical formulae are found to be in excellent agreement with numerical ... 
Multiplicity of subharmonic solutions of forced Hamiltonian systems near an equilibrium
(Springer Verlag (Germany), 1989)We prove existence and multiplicity of long time periodic solutions for a class of nonlinear nonautonomous Hamiltonian systems locally near an equilibrium solution. The result relies on a variational principle and on the ... 
Multiplicity of kTperiodic solutions near a given Tperiodic solution for nonlinear Hamiltonian systems
(Khayyam Publishing, 1989) 
Radial gauge in poincare gauge fieldtheories
(AMER INST PHYSICS, 1990)The generalization of the Fock–Schwinger or ‘‘radial’’ gauge condition xiAi =0 to the gauge theories of the Poincaré group, which describe the gravitational field, is treated. It is shown that the choice of a radial gauge ... 
Forced oscillations for singular dynamical systems with an application to the restricted three body problem
(Elsevier, 1991)We consider forced dynamical systems with two degrees of freedom having singular potentials and we prove existence of infinitely many classical (noncollision) periodic solutions. These solutions have a prescribed rotation ... 
Initial thermalization of photoexcited carriers in GaAs studied by femtosecond luminescence spectroscopy
(AMERICAN PHYSICAL SOC, 1991)Relaxation of a nonequilibrium distribution of electrons and holes in GaAs following femtosecond photoexcitation is investigated via spectrally and timeresolved luminescence. A rapid onset of luminescence over a broad ... 
Homoclinics for Lagrangian systems on Riemannian manifolds
(Dynamic Publishers Atlanta, 1992) 
Femtosecond luminescence spectroscopy of carrier thermalization in GaAs and InP
(IOP PUBLISHING LTD, 1992)Thermalization of a nonequilibrium distribution of electrons and holes generated by femtosecond photoexcitation is studied in GaAs and InP via spectrally and temporally resolved luminescence. In both materials, a rapid ... 
Vacuum correlations in quantum gravity
(ELSEVIER SCIENCE BV, 1992)We give a lowestorder estimation of some invariant correlation functions of quantized Einstein gravity in any dimension N > 2. The nonperturbative evaluation of such functions would play an important role in the Monte ... 
The propagator in the radial gauge
(AMER INST PHYSICS, 1992)The solutions of the equation for the propagator in the radial gauge x(mu)A(mu)(x) = 0 are studied. After finding a particular solution GAMMA(murho)(x,y), the most general solution G(murho)0(x,y) of the homogeneous ... 
On the motion of test particles in a fluctuating gravitational field
(AMER INST PHYSICS, 1992)In this paper the "free fall" motion of a test tetrad in a weak gravitational field is studied. This is done with the intention of exploring the geometry locally through geodesics and parallel transport. By use of the ... 
Geodesic round trips by parallel transport in quantum gravity
(AMERICAN PHYSICAL SOC, 1993)We study the vacuum correlations of a gravitational field in any dimension N > 2 using the perturbative expansion to order G. It is known that the usual Green's functions are meaningless in quantum gravity; moreover, we ... 
A Comparison of Monte Carlo and Cellular Automata Approaches for Semiconductor Device Simulation
(IEEEINST ELECTRICAL ELECTRONICS ENGINEERS INC, 1993)We present a detailed comparison of Monte Carlo and cellular automata approaches as applied to the study of nonequilibrium transport and semiconductor device simulation. We show that the novel cellular automata (CA) technique ... 
The radial gauge propagators in quantum gravity
(ACADEMIC PRESS INC JNLCOMP SUBSCRIPTIONS, 1993)We give a general procedure for extracting the propagators in gauge theories in the presence of a sharp gauge fixing and we apply it to derive the propagators in quantum gravity in the radial gauge, both in the first and ... 
DeadSpace Effects Under NearBreakdown Conditions in AlGaAs/GaAs HBT’s
(IEEEINST ELECTRICAL ELECTRONICS ENGINEERS INC, 1993)By using a selfconsistent Monte Carlo simulation, we demonstrate the importance of deadspace effects in the nearavalanche regime of AlGaAs/GaAs HBT's. We show that the spacedependent ionization coefficient reaches its ...