Theory of spin hall conductivity in n-doped GaAs

We develop a theory of extrinsic spin currents in semiconductors, resulting from spin-orbit coupling at charged scatterers, which leads to skew-scattering and side-jump contributions to the spin-Hall conductivity. Applying the theory to bulk n-GaAs, without any free parameters, we find spin currents that are in reasonable agreement with experiments by Kato et al. [Science 306, 1910 (2004)].     

Asymmetric quantum shot noise in quantum dots

We analyze the frequency-dependent noise of a current through a quantum dot which is coupled to Fermi leads and which is in the Coulomb blockade regime. We show that the asymmetric shot noise, as a function of detection frequency, shows steps and becomes super-Poissonian. This provides experimental access to the quantum fluctuations of the current. We present an exact calculation of the noise for a single dot level and a perturbative evaluation of the noise in Born approximation (sequential tunneling regime but without Markov approximation) for the general case of many levels with charging interaction.     

A Semigroup Approach to Boundary Feedback Systems

In this paper we convert a (linear abstract) initial boundary value problem into an abstract Cauchy problem on some product space and use semigroup methods to solve it. In particular, we apply spectral theory in order to discuss stability under boundary feedback.     

The Specific-Force Performance Parameter for Electromagnetic Launchers

A new electromagnetic-launcher (EML) performance parameter called the specific force is presented and analyzed in this paper. The specific force is the second derivative of the EML's force equation with respect to current and represents the force generated by the EML per unit square ampere, i.e., the EML's current efficiency. The specific force is independent of operating current and is defined for EMLs utilizing linear and nonlinear magnetic materials. The second derivative is termed as the specific force, since it unifies the various EML geometries so that only one force equation is required. The specific force, together with the energy-conversion efficiency, can be used as criterion to evaluate and compare EML geometries for various applications. The specific force for conventional railguns, augmented railguns, conventional helical launchers, and high-efficiency helical launchers is derived in this paper. The experimental performance of conventional railguns, augmented railguns, and conventional helical launchers are also analyzed in terms of their specific-force parameters.      

Ueber die Eigenschaften des Glycocolls

Ohne Zusammenfassung