Schemes generating entangled states and entanglement swapping between photons and three-level atoms inside optical cavities for quantum communication

We propose quantum information processing schemes based on cavity quantum electrodynamics (QED) for quantum communication. First, to generate entangled states (Bell and Greenberger–Horne–Zeilinger [GHZ] states) between flying photons and three-level atoms inside optical cavities, we utilize a controlled phase flip (CPF) gate that can be implemented via cavity QED). Subsequently, we present an entanglement swapping scheme that can be realized using single-qubit measurements and CPF gates via optical cavities. These schemes can be directly applied to construct an entanglement channel for a communication system between two users. Consequently, it is possible for the trust center, having quantum nodes, to accomplish the linked channel (entanglement channel) between the two separate long-distance users via the distribution of Bell states and entanglement swapping. Furthermore, in our schemes, the main physical component is the CPF gate between the photons and the three-level atoms in cavity QED, which is feasible in practice. Thus, our schemes can be experimentally realized with current technology.     

Pulsed Laser Processing of Carbon and Silicon Clusters and Thin Films

Abstract

Several new processes have been developed for the preparation of fullerenes and thin films by using a pulsed excimer laser. The irradiation of a pulsed KrF excimer laser beam onto a C₆₀ powder target produced single phase C₆₀ thin films when the laser energy fluence was in the range between 40 and 50mJ/cm². By atomic force microscopy, the laser-deposited C₆₀ thin film was verified to have a surface far smoother that the surfaces of films produced by the conventional evaporation method. The stainless steel rods coated with this film exhibited an excellent tribological property. Cluster formation from SiC and other carbides MC_n(M=Ti,W,B) was investigated by laser desorption time-of-flight mass spectrometry. No clear indication was observed for the production of such clusters as (SiC)₆₀ and (M_xC_60-x) from the sintered targets directly as well as from the films laser deposited from the targets. However, C₆₀ and C₇₀ were found to exists in the laser-deposited films, indicating a new applicability of pulsed laser processing for segregative cluster synthesis from solid solution. Preliminiary results on thin film deposition via pulsed ablation of (Ba,Na)_xSi₄₆ clathrate were also presented.     

Output Feedback Regulation of a Class of Lower Triangular Nonlinear Systems with Arbitrary Unknown Measurement Sensitivity

International Journal of Control, Automation and Systems - In this paper, a regulation problem for a class of lower triangular nonlinear systems under unknown measurement sensitivity by output...     

Global regulation of a class of nonlinear systems with high-order triangular type nonlinearity

The problem of global regulation is investigated for a class of nonlinear systems which contain some high-order terms. We propose a high-order scaling state-feedback controller with appropriate dynamic gains. Compared to existing results, the condition on the nonlinearity is flexible due to the freedom of choosing the bounding positive function of the nonlinearity. Thus, the nonlinear systems with some high-order nonlinearities which do not belong to existing conditions can be globally regulated.     

Fast Regulation Control of a Class of Input-delayed Linear Systems with Pre-feedback

A control problem of a class of input-delayed linear systems is considered in this paper. Due to the delay τ in the input, any designed feedback controller can only be engaged after t ≥ τ. Then, this can become the cause of slow regulation since any feedback information cannot be available during the delay. So, the initial function defined for -τ ≤ t ≤ 0 is engaged as an ‘initial non-feedback input’ for 0 ≤ t ≤ τ, which governs the system behavior during this initial time period. There have been numerous research results on the control of input-delayed linear systems by far. Yet, there have been no results on the examination and design of this initial function. Utilizing a time optimal control in the existing results, we show that if some pre-feedback as the initial function is engaged, the system response of the input-delayed linear system can be much improved, and a bang-bang input function is a good candidate as a pre-feedback which can provide better starting state values for the state feedback controller in order to perform the fast regulation. Two examples are given for the illustration of our results.     

The effect of nonequilibrium condensation on hysteresis phenomenon of under-expanded jets

Under-expanded jets which are discharged from an orifice or a nozzle have long been subject of researches for aeronautical and mechanical applications. Provided that the jet pressure ratio and nozzle configuration are known, the major features of the steady jet are now well known. However, the jet pressure ratio is often varied even during the process in many practical applications. Many questions remain unanswered with regard to how the supersonic jet responds to the transient process of the pressure ratio and whether the steady jet data for a specific pressure ratio can still bear the same during the transient process of pressure ratio. In the present study, the hysteric phenomenon of under-expanded jets has been investigated with the help of computational fluid dynamics methods. The under-expanded jets of both dry and moist air have been employed to investigate the transient processes of the pressure ratio. The effects of nonequilibrium condensation occurring in the under-expanded moist air jets are explored on the hysteresis phenomenon. It is known that under-expanded air jet produced during the startup transient of jet behaves differently from the shutdown transient process, leading to the hysteric phenomenon of under-expanded jet. It is also known that the moist air jet reduces the hysteric phenomenon, compared with the dry air jet, and that non-equilibrium condensation which occurs in the underexpanded moist air jet is responsible for these findings. This paper was recommended for publication in revised form by Associate Editor Do Hyung Lee Heuy-Dong Kim received his B.S. and M.S. degrees in Mechanical Engineering from Kyungpook National University, Korea, in 1986 and 1988, respectively. He then received his Ph.D. degree from Kyushu University, Japan, in 1991. Dr. Kim is currently a Professor at the School of Mechanical Engineering, Andong National University, Korea. His research interests include High-Speed Trains, Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Flow Measurement, Aerodynamic Noises and Supersonic Wind Tunnels. Min-Sung Kang received his B.S. and M.S degrees in Mechanical Engineering from Andong National University, Korea, in 2007 and 2009, respectively. Mr. Kang is currently a researcher at the School of Mechanical Engineering at Andong National University, Korea. His research interests include cavity and supersonic nozzle flows. Yumiko Otobe received her B.S. degree in Faculty of Engineering from Yamaguchi University, Japan, in 1978. She then received her Eng. D. degree from Saga University, Japan, in 2007. Dr. Otobe is currently a Research Associate at the Department of Control & Information Systems Engineering, Kitakyushu National College of Technology, Japan. Dr. Otobe’s research interests include sonic and supersonic jets of various gases as well as nonequilibrium condensation phenomena. Toshiaki Setoguchi received his B.S. degree in Mechanical Engineering from Tokyo University of Agriculture and Technology, Japan, in 1976. He then received his M.S. and Ph.D. degrees from Kyushu University, Japan, in 1978 and 1981, respectively. Dr. Setoguchi is currently a Professor at the Department of Mechanical Engineering, Saga University, Japan. His research interests include Nonequilibrium Condensation, Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Aerodynamic Noises and Turbomachinery.     

Dynamic gain control with a matrix inequality approach to uncertain systems with triangular and non-triangular nonlinearities

We consider the global regulation problem of uncertain systems with both triangular and non-triangular nonlinearities. For the global regulation in the presence of non-triangular nonlinearities, we propose a dynamic gain controller designed by using power order conditions and a matrix inequality condition imposed on non-triangular nonlinearities. Compared with the existing results, the proposed control method allows a class of nonlinear systems that have not been treated before. Analysis and examples are given to prove the general applicability of our control method.     

Universal control of nonlinear systems with unknown nonlinearity and growth rate by adaptive output feedback

Over the past several years, triangular or feedforward nonlinear systems have received considerable attention and there are many independent results for stabilization or regulation problems. These results are often specifically targeted for only one of these systems and they are applicable when the system nonlinearity is known a priori. In this paper, we propose an adaptive output feedback controller coupled with switching logic to universally regulate both triangular and feedforward systems without recognizing the system nonlinearity. Moreover, with our control scheme, the linear growth rate is not required to be known.     

Perfect Reconstructable Decimated One-Dimensional Empirical Mode Decomposition Filter Banks

This paper introduces decimated filter banks for the one-dimensional empirical mode decomposition(1D-EMD).These filter banks can provide perfect reconstruction and allow for an arbitrary tree structure.Since the EMD is a data driven decomposition,it is a very useful analysis instrument for non-stationary and non-linear signals.However,the traditional 1D-EMD has the disadvantage of expanding the data.Large data sets can be generated as the amount of data to be stored increases with every decomposition level.The 1D-EMD can be thought as having the structure of a single dyadic filter.However,a methodology to incorporate the decomposition into any arbitrary tree structure has not been reported yet in the literature.This paper shows how to extend the 1D-EMD into any arbitrary tree structure while maintaining the perfect reconstruction property.Furthermore,the technique allows for downsampling the decomposed signals.This paper,thus,presents a method to minimize the data-expansion drawback of the 1D-EMD by using decimation and merging the EMD coefficients.The proposed algorithm is applicable for any arbitrary tree structure including a full binary tree structure.