considering a temperature dependent two-level quantum system, we have numerically solved the landau-zener transition problem. the method includes the incorporation of temperature effect as a thermal noise added schrödinger equation for the construction of the hamiltonian. here, the obtained results which describe the changes in the system including the quantum states and the transition probabil...

static properties, relatively intensity noise and intensity modulation response in quantum cascade lasers (qcls) studied theoretically in this paper. the present rate equations model consists of three equations for the electrons density in the conduction band and one equation for photons density in cavity length. two equations were derived to calculate the noise and modulation response. calcula...

A model of a low noise high quantum efficiency n+np Germanium Photodiode utilizing ion implantation technique and subsequent drive-in diffusion in the n layer is presented. Numerical analysis is used to study the influence of junction depth and bulk concentration on the electric field profile and quantum efficiency. The performance of the device is theoretically treated especially at the wave-l...

Considering a temperature dependent two-level quantum system, we have numerically solved the Landau-Zener transition problem. The method includes the incorporation of temperature effect as a thermal noise added Schrödinger equation for the construction of the Hamiltonian. Here, the obtained results which describe the changes in the system including the quantum states and the transition pro...

a quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. the initial atomic coherence plays an essential role. at steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser field. ...

A notion of quantum black noise is considered. Quantum black noise is an analogue of quantum white noise but it acts in a Fock space with indefinite metric. Quantum white noise describes the leading term in the stochastic limit approximation to quantum dynamics while quantum black noise describes corrections to the leading term. We obtain and study generalized quantum stochastic equations descr...

A notion of quantum multipole (in particular, dipole) noise is considered. Quantum dipole noise is an analogue of quantum white noise but it acts in a Fock space with indefinite metric. Quantum white noise describes the leading term in the stochastic limit approximation to quantum dynamics while quantum multipole noise describes corrections to the leading term. We obtain and study generalized q...