Search results for " Electron Spin relaxation"
showing 3 items of 3 documents
Metastability and Relaxation in Quantum and Mesoscopic Systems
2013
The transient dynamics and the relaxation of three quantum and mesoscopic systems are investigated. In particular we analyze: (i) a long Josephson junction (LJJ) driven by a non-Gaussian Lévy noise current; (ii) a metastable quantum dissipative system driven by an external periodical driving; and (iii) the electron spin relaxation process in n-type GaAs crystals driven by a fluctuating electric field. Specifically, in the first system the LJJ phase evolution is described by the perturbed sine-Gordon equation. We find the noise enhanced stability and resonant activation phenomena, by investigating the mean escape time as a function of the bias current frequency, noise intensity and length of…
Monte Carlo Simulation of Electron Dynamics in Doped Semiconductors Driven by Electric Fields: Harmonic Generation, Hot-Carrier Noise and Spin Relaxa…
2011
In solid state electronics the miniaturization of integrated circuits implies that, even at moderate applied voltages, the components can be exposed to very intense electric fields. Advances in electronics push the devices to operate also under cyclostationary conditions, i.e. under large-signal and time-periodic conditions. A main consequence of this fact is that circuits exhibit a strongly nonlinear behavior. Furthermore, semiconductor based devices are always imbedded into a noisy environment that could strongly affect their performance, setting the lower limit for signal detection in electronic circuits. For this reason, to fully understand the complex scenario of the nonlinear phenomen…
Nonlinear relaxation in quantum and mesoscopic systems
2013
The nonlinear relaxation of three mesoscopic and quantum systems are investigated. Specifically we study the nonlinear relaxation in: (i) a long Josephson junction (LJJ) driven by a non-Gaussian Lévy noise current; (ii) a metastable quantum open system driven by an external periodical driving; and (iii) the electron spin relaxation process in n-type GaAs crystals driven by a fluctuating electric field. In the first system the LJJ phase evolution is described by the perturbed sine-Gordon equation. Two well known noise induced effects are found: the noise enhanced stability and resonant activation phenomena. We investigate the mean escape time as a function of the bias current frequency, nois…