Controlling quantum coherence of atom laser by light with strong strength

A new method for controlling the quantum coherence of atom laser by applying input light with strong strength is presented within the framework of quantum dynamical theory. Unlike the case of rotating wave approximation(RWA), we show that the non-classical properties, such as sub-Poisson distribution and quadrature squeezed effect, can appear in the output atom laser beam with time. By choosing suitable initial RF phase, a steady and brighter output of squeezed coherent atom laser is also available.     

Spectroscopic characterization of core and shell regions in monolayer protected gold nanoparticles

We report studies on the structure of the metallic core and the alkyl cap layer in monolayer protected gold nanoparticles having sizes down to 1.6 nm. These particles are obtained by laser ablating gold targets in alkane-thiol solutions at different concentrations. The electronic structure of gold core and the vibrational properties of the capping hydrocarbon chains reveal effects connected with the nanosized nature of the particles.     

Infra-red free-carrier absorption due to impurity scattering in semiconducting quantum well structures

The theory of free-carrier absorption (FCA) is developed, in the extreme quantum limit when the carriers are assumed to populate only the lowest quantized energy level, for quasi-two and one-dimensional semiconducting quantum well structures where the carriers are scattered by ionized impurities. The radiation field is assumed to be polarized in the plane of the layer in the quasi-two-dimensional case and along the length of the wire in the quasi-one-dimensional case. Expressions for FCA are obtained for the cases where the impurities are either in the well (background impurities) or outside the well (remote impurities). Variation of FCA is numerically studied with photon frequency and well width.     

Time evolution of non-Hermitian quantum systems and generalized master equations

We inquire into the time evolution of quantum systems associated with pseudo-or quasi-Hermitian Hamiltonians. We obtain, in the pseudo-Hermitian case, a generalized Liouville-von Neumann equation for closed systems. We show that quantum systems with quasi-Hermitian Hamiltonians admit the proper interpretation in terms of open quantum system and derive a generalized Lindblad-Kossakowski equation. Finally, we extend such formalism to the study of decaying systems. Partially supported by PRIN “Sintesi”.     

推广x重新标度模型的重标度参数经验公式

给出了推广x重新标度模型的重标度参数经验公式,其中建立了重标度参数与原子核的平均结合能之间的联系,由该公式可以得出A≥12的所有核的重标度参数值,利用这些参数值可以计算有关核过程并做出预言.     

Generic entangling through quantum indistinguishability

We present a general scheme for entangling any degree of freedom of two uncorrelated identical particles from independent sources by a combination of two-particle interferometry and which-way detection. We show that this entanglement generation procedure works for completely random initial states of the variable to be entangled. We also demonstrate a curious complementarity exhibited by our scheme and its applications in estimating the generated entanglement as a function of wave packet overlap at the beamsplitter.     

Investigations of Solid State Dynamics at the NRSSR Beamline at PETRA II. An Overview

The present status of the new nuclear resonance beamline PETRA 1 at HASYLAB, DESY, Hamburg is described. Besides an overview of the experimental setup some examples of recent experiments are given. Those cover the main applications, i.e., inelastic scattering from iron alloys and quasielastic scattering from glass-forming liquids. This revised version was published online in August 2006 with corrections to the Cover Date.     

On Quantum Team Games

Recently Liu and Simaan (2004) convex static multi-team classical games have been introduced. Here they are generalized to both nonconvex, dynamic and quantum games. Puu's incomplete information dynamical systems are modified and applied to Cournot team game. The replicator dynamics of the quantum prisoner's dilemma game is also studied.     

Field Theory Methods in Classical Dynamics

A Dirac picture perturbation theory is developed for the time evolution operator in classical dynamics in the spirit of the Schwinger–Feynman–Dyson perturbation expansion and detailed rules are derived for computations. Complexification formalisms are given for the time evolution operator suitable for phase space analyses, and then extended to a two-dimensional setting for a study of the geometrical Berry phase as an example. Finally a direct integration of Hamilton's equations is shown to lead naturally to a path integral expression, as a resolution of the identity, as applied to arbitrary functions of generalized coordinates and momenta.     

V20+离子1s23d-1s2nf的跃迁能和振子强

用全实加关联方法计算了类锂V20+离子1s23d-1s2nf的跃迁能和偶极振子强度.依据量子亏损理论, 确定了1s2nf系列的量子数亏损,用这些作为能量的缓变函数的量子亏损,实现对该Rydberg系列任意高激发态(n≥10)的能量的可靠预言.将这些分立态振子强度与量子亏损理论相结合,得到在电离域附近束缚态间的偶极跃迁振子强度以及束缚态-连续态跃迁的振子强度密度,从而将V20+离子的这一重要光谱特性的理论预言外推到整个能域.