Volume 32, Issue 12, December 2006
Index of content:
- LOW-DIMENSIONAL AND DISORDERED SYSTEMS
32(2006); http://dx.doi.org/10.1063/1.2400695View Description Hide Description
We study theoretically the current-voltage characteristics, shot noise, and full counting statistics of a quantum wire double-barrier structure. We model each wire segment by a spinless Luttinger liquid. Within the sequential tunneling approach, we describe the system’s dynamics using a master equation. We show that at finite bias the nonequilibrium distribution of plasmons in the central wire segment leads to increased average current, enhanced shot noise, and full counting statistics corresponding to a super-Poissonian process. These effects are particularly pronounced in the strong interaction regime, while in the noninteracting case we recover results obtained earlier using detailed-balance arguments.
32(2006); http://dx.doi.org/10.1063/1.2400696View Description Hide Description
This paper reports the application of scanning electron microscopy, x-ray diffraction, and photoluminescence techniques for characterization of ZnSe nanocrystals grown on GaAs (100) substrate from the vapor phase. The characterization techniques used show evidence for the coexistence of two sets of nanocrystals with rather different characteristic sizes. In addition, the lowest energy levels of spherically shaped nanocrystals are calculated in the framework of the effective-mass approximation and compared with photoluminescence data.
Electron diffraction study of two-component clusters Ar–Kr: Features of the nucleation, growth mechanisms, and structural states32(2006); http://dx.doi.org/10.1063/1.2400697View Description Hide Description
The structure and growth processes of clusters formed in adiabatically expanding supersonic jets of gaseous mixtures of rare gases are investigated for the first time. Ar–Kr mixtures containing 0.1, 0.5, 2.5, and 20% Kr atoms are studied at temperatures and pressures of the gaseous mixtures at the nozzle entrance and and . The experiments give a number of results that shed light on the picture of cluster formation in Ar–Kr gaseous mixtures. It is established that the mechanisms of cluster formation depend substantially on the krypton impurity concentration and the temperature of the gaseous mixture at the nozzle entrance. The evolution of the character of the cluster formation, from homogeneous to heterogeneous, is traced. The intensification of rare-gas cluster growth by an impurity is revealed for the first time, and the concentration dependence of the transition from a process of formation of solid solutions to the formation of clusters containing only impurity krypton is traced.