Nonadiabatic Phase and Persistent Currents for System of Spin-1/2 Particles in Presence of Electromagnetic Fields and Spin-Orbit Interaction

We present a comprehensive view and details of calculations on Aharonov-Anandan phase for the charged particles in the external electric and magnetic fields for a nonadiabatic process. We derive, with consideration of a spin-orbit interaction and Zeemann Splitting, the persistent currents as a response to an Aharonov-Casher topological interference effect in one-dimensional mesoscopic ring. We also establish a connection to Berry adiabatic phase with deduced dynamical-nature dependence in the nonadiabatic process. The second quantization representation has also been employed in exhibition of persistent currents in the many-body case.     

Asymptotic Behaviour of Randomly Reflecting Billiards in Unbounded Tubular Domains

We study stochastic billiards in infinite planar domains with curvilinear boundaries: that is, piecewise deterministic motion with randomness introduced via random reflections at the domain boundary. Physical motivation for the process originates with ideal gas models in the Knudsen regime, with particles reflecting off microscopically rough surfaces. We classify the process into recurrent and transient cases. We also give almost-sure results on the long-term behaviour of the location of the particle, including a super-diffusive rate of escape in the transient case. A key step in obtaining our results is to relate our process to an instance of a one-dimensional stochastic process with asymptotically zero drift, for which we prove some new almost-sure bounds of independent interest. We obtain some of these bounds via an application of general semimartingale criteria, also of some independent interest.     

Diagnosis, prescription, and prognosis of a bell-state filter by quantum process tomography

We apply the techniques of quantum process tomography to characterize errors and decoherence in a prototypical two-photon operation, a singlet-state filter. The quantum process tomography results indicate a large asymmetry in the process and also the required operation to correct for this asymmetry. We quantify residual errors and decoherence of the filtering operation after this modification.     

Four-wave mixing: Photon statistics and the impact on a co-propagating quantum signal

We reconstruct the photon statistics of a single-photon source based on the stimulated four-wave mixing (FWM) process. We find that the statistics of the source goes from thermal, at a low power regime, to Poissonian, at a high power regime. We also study the impact of the FWM process on a co-propagating coherent quantum signal in a wavelength-division multiplexed (WDM) lightwave system. The statistics of the quantum signal changes from Poissonian to thermal when a low power is used, and remains Poissonian for a higher power. A multithermal regime is also observed when a moderate power is used.     

PageRank model of opinion formation on Ulam networks

We consider a PageRank model of opinion formation on Ulam networks, generated by the intermittency map and the typical Chirikov map. The Ulam networks generated by these maps have certain similarities with such scale-free networks as the World Wide Web (WWW), showing an algebraic decay of the PageRank probability. We find that the opinion formation process on Ulam networks has certain similarities but also distinct features comparing to the WWW. We attribute these distinctions to internal differences in network structure of the Ulam and WWW networks. We also analyze the process of opinion formation in the frame of generalized Sznajd model which protects opinion of small communities.     

Engineering Two-Atom Thermal Entanglement via Two-Photon Process

We study that two atoms simultaneously interact with a single mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can employ the different couplings to produce the two-atom thermal entanglement in two-photon process. The different atomic spontaneous emission rates are also utilizable in generating thermal entanglement. We also investigate the effect of the can obtain a strong and steady entanglement.     

磁阻尼多功能演示仪(Ⅱ型)

将磁阻尼演示仪与PASCO力传感器相连,通过计算机采集数据,实现对磁阻尼振动若干物理过程的演示,并且用简化模型分析了阻尼振动的物理过程.     

Reversible Measurement on Quantum States of Trapped-Ion Qubits

We consider reversible quantum measurement process with ultracold trapped ions. Two schemes will be proposed based on currently available experimental techniques. We also study the measurement process with electronic shelving amplification.     

Coherent manipulation of light pulses in a multilevel atomic system

We consider the quantum memory process in general multilevel atomic systems with electromagnetically induced transparency (EIT). We discuss the pulse-matching phenomenon in this general EIT scheme. We also review a recent proposal to create tightly localized stationary pulses by using counterpropagating pump fields. The advantages in creating the stationary pulses with the general EIT system are also discussed.     

Blocking and Dimer Processes on the Cayley Tree

We show that the equilibrium distribution for the dimer process on the finite Cayley tree tends to a translation invariant limit as the size of the tree tends to infinity. The same is true for the blocking process except when there is a phase transition, in which case there are two limits, each a one-step translation of the other. We also find correlations for occupation probabilities.     

Observation of atom pairs in spontaneous four-wave mixing of two colliding Bose-Einstein condensates

We study atom scattering from two colliding Bose-Einstein condensates using a position sensitive, time resolved, single atom detector. In analogy to quantum optics, the process can also be thought of as spontaneous, degenerate four-wave mixing of de Broglie waves. We find a clear correlation between atoms with opposite momenta, demonstrating pair production in the scattering process. We also observe a Hanbury Brown-Twiss correlation for collinear momenta, which permits an independent measurement of the size of the pair production source and thus the size of the spatial mode. The back-to-back pairs occupy very nearly two oppositely directed spatial modes, a promising feature for future quantum optics experiments.     

N-state Markov jump process

A certain N-state Markov jump process is studied in connection with laser mode hopping and phase switching. We show that the Chapman-Kolmogorov-Smoluchowski equations can be solved exactly to yield a simple expression for the transition probability function. Some properties of such a process and its connection with the related pre-gaussian process are examined. We also study the atomic response to excitation by a laser whose phase or frequency exhibits such jumps, and the non-gaussian property of the line shape is discussed.     

Associated production of a KK-graviton with a Higgs boson via gluon fusion at the LHC

In order to solve the hierarchy problem, several extra-dimensional models have received considerable attention. We have considered a process where a Higgs boson is produced in association with a KK-graviton (G _KK) at the LHC. At the leading order, this process occurs through the gluon fusion mechanism gg→hG _KK via a quark loop. We compute the cross section and examine some features of this process in the ADD model. We find that the quark in the loop does not decouple in the large quark-mass limit just as in the case of gg→h process. We compute the cross section of this process for the case of the RS model also. We examine the feasibility of this process being observed at the LHC.     

Metastability of thed-dimensional contact process

We prove that thed-dimensional supercritical contact process exhibits metastable behavior, in the pathwise sense. This is done by proving the property of thermalization and using Mountford's theorem. We also extend some previous results on the loss of memory of the process.     

On the diffusion of a fast molecule

We consider the motion of a heavy particle in interaction with an infinite ideal gas of slow atoms. We prove that the velocity of the heavy particle is, in a suitable limit, modeled by a deterministic process. We also treat the process of rescaled velocity fluctuations around a certain deterministic motion and show that this is appropriately modeled by a nonhomogeneous diffusion process.Supported in part by NSF grants PHY-8201708 and DMR81-14726.Supported in part by NSF grant PHY-8003298 and the Seton Hall University, Research and Faculty Development Council.     

Plane Partitions with Two-Periodic Weights

We study scaling limits of skew plane partitions with periodic weights under several boundary conditions. We compute the correlation kernel of the limiting point process in the bulk and near turning points on the frozen boundary. The system develops pairs of turning points (points where three different phases meet), which are separated by “semi-frozen” regions. We show that the point process at such a turning point is a pair of non-trivially correlated GUE minor processes. In the limit when all weights become the same, i.e. in the homogeneous case, such a pair of turning points collapses into a single turning point and the local process becomes the GUE minor process. We also study an intermediate regime when the weights are periodic but all converge to 1. In this regime the limit shape and correlations in the bulk are the same as in the case of homogeneous weights, and periodicity is not visible in the bulk. However, the process at turning points is still not the GUE minor process.     

Skellam Type Processes of Order k and Beyond

In this article, we introduce the Skellam process of order k and its running average. We also discuss the time-changed Skellam process of order k. In particular, we discuss the space-fractional Skellam process and tempered space-fractional Skellam process via time changes in Skellam process by independent stable subordinator and tempered stable subordinator, respectively. We derive the marginal probabilities, Lévy measures, governing difference-differential equations of the introduced processes. Our results generalize the Skellam process and running average of Poisson process in several directions.     

Dynamics of quantum discord in the purification process

We investigate the dynamics of quantum discord during the purification process. In the case of Werner states, it is shown that quantum discord is increased after a round of purification protocol. Furthermore, quantum mutual information and classical correlation is also increased during this process. We also give an analytic expression for a class of higher dimensional states which have additive quantum discord.     

在LiNbO3:Fe晶体中暗辐照对光束从自散焦向自聚焦转换过程的影响

基于二维带输运模型，研究了LiNbO3:Fe晶体中光束从自散焦向自聚焦动态转换过程.结果表明暗辐照在动态转换过程中起着非常重要的作用，当暗辐照较小时动态转换过程才发生.在暗辐照较小的情况还分析了热释电效应对动态转换过程的影响. 关键词： 光生伏打效应 暗辐照 自散焦 自聚焦 LiNbO3:Fe