bluuebunny/crossref_metadata_2025 huggingface dataset:
Process-induced mechanical stress effects on deep submicron CMOS device
Authors: Li Rui  , Wang Qing-Dong  ,   (1)上海宏力半导体制造有限公司，上海  201203; (2)中国科学院上海微系统与信息技术研究所，上海  200050；中国科学院研究生院，北京  100049；上海宏力半导体制造有限公司，上海  201203
Published: December 2020

With the continuous downscaling of CMOS technology, process-induced mechanical stress effects become remarkable with the shrinkage of active region. Many processing steps individually or collectively contribute to mechanical stress development. The stress results in not only the layout dependency of device performances, but also diverse reliability issues, which would shorten the chip lifetime. In many cases, stress-related problems are determinative of IC yield. Here, based on the summary of mechanical stress sources, we review the achievements to date in observing and understanding these stress problems, and propose the prospective considerations when analyzing stress-related phenomenon.
PbS quantum dot doped glass prepared by sol-gel method
Authors: Xiang Wei-Dong  , Tang Shan-Shan  , Zhang Xi-Yan  , Yang Xin-Yu  , Zhang Yan-Hua  ,   (1)长春理工大学材料科学与工程学院，长春  130022; (2)温州大学化学与材料学院，温州  325035
Published: December 2020

Na2O-B2O3-SiO2 glasses doped with semiconductor PbS quantum dots were fabricated via a sol-gel routine in this paper. The influence of different heat treatment on microstructure of glass were made, and characterization of the micro-crystals doped in glass matrix were made by varies methods. The result of N2 adsorption-desorption shows that the diameter of pores in the interior of glass diminishes, with increasing temperature, and the pores totally disappear at last. IR spectra indicate that network structure of glass is form at low temperature, and becomes compact at higher temperature. The PbS crystals are found in the glass matrix by both X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM), and the average size of the crystallites is 3.5nm in diameter. Comparing with the bulk PbS, the absorption edge in the optical absorption spectra of glass containing PbS quantum dots exhibits a blue shift and shows obvious quantum size effect. The nonlinear refractive index (γ) of the glass doped with PbS micro-crystals was determined by Z-scan technology to be -1.6×10-11cm2/GW.
Integral invariants of a generalized Birkhoff system
Authors: Mei Feng-Xiang  , Cai Jian-Le  ,   (1)北京理工大学力学系，北京  100081; (2)杭州师范大学理学院，杭州  310018
Published: December 2020

Integral invariants of a generalized Birkhoff system are studied in this paper. The condition under which the integral invariants exist in the system is given. A linear integral invariant, a universal integral invariant and an absolute integral invariant of second order of the system are obtained under the given condition. An example is given to illustrate the application of the result.
Switch effect of Bose-Einstein condensates in a triple-well potential
Authors: Wang Hai-Lei  , Yang Shi-Ping  ,   (1)河北师范大学物理科学与信息工程学院,石家庄  050016; (2)河北师范大学物理科学与信息工程学院,石家庄  050016；北京应用物理与计算数学研究所,北京  100088
Published: December 2020

We propose a scheme utilizing mean-field approach to exhibits the switching effect in a symmetrical Bose-Einstein condensate triple-well potential. Our study shows that tunneling from the left well to the right well of a large number of atoms can be controlled by a small amount of atoms in the middle well. We also discuss the role played by the relative phase and the relation between the zero-point and the critical value of working range. The potential applications of our model are pointed out.
Multi-value cellular automata model for mixed non-motorized traffic flow
Authors: Li Xin-Gang  , Gao Zi-You  , Zhao Xiao-Mei  , Jia Bin  ,   (1)北京交通大学轨道交通控制与安全国家重点实验室，北京  100044；北京交通大学交通运输学院，北京  100044; (2)北京交通大学交通运输学院，北京  100044
Published: December 2020

In this paper, a multi-valued cellular automata model for mixed non-motorized traffic flow is proposed and the simulation results are studied. The mixed non-motorized traffic flow is mainly composed of bicycles and tricycles in Chinese towns. According to the fact that bicycles and tricycles have different sizes, a bicycle is assumed to occupy one unit cell space and a tricycle two units of cell space. The simulation results show that: In the system with slow bicycles and tricycles, the ratio and the first moving probability of tricycles do not affect the flux, however, the first moving probability of tricycles will impact on the average velocity of bicycles and tricycles. In the system with fast bicycles and tricycles, the multiple state effect appears both in free flow and congested flow regions under the deterministic case, and it disappears when the fast bicycles has the randomization effect.
A density-functional theory study on the chemisorption and STM images of Ag(100)/O surface
Authors: Chen Wen-Bin  , Tao Xiang-Ming  , Chen Xin  , Tan Ming-Qiu  ,   浙江大学物理系，杭州  310027
Published: December 2020

In this article we have investigated the influence of oxygen adsorption on the surface geometry and electronic properties of Ag(100) surface by using the density-functional theory calculations. The total energy calculations based on projector-augmented wave (PAW) method have been preformed to describe the adsorption geometry at several coverages of oxygen adsorption including p(1×1), c(2×2), and (21/2×221/2)R45°, and a series of main physical properties at these coverages on Ag(100) surface such as the surface relaxation, adsorption energy, work function and so on. The results presented in this work show that for an Ag(100) (21/2×221/2)R45°-2O geometry, the most stable atomic structure is a type of missing-row reconstruction. Eventually, this structural change causes various displacements of surface atoms which have been calculated in this work. The calculations on the local density of states reveal that in the Ag(100) (21/2×221/2)R45°-2O geometry the cohesive effect between the adsorbed oxygen atoms and the substrate Ag layer is essentially due to the sufficient Ag4d-O2p orbital hybridization. Finally we have simulated the STM images for several bias-voltages and tip heights, providing experiments with abundant data and theoretical support.
Electromagnetically induced absorption and electromagnetically induced transparency in an optical-radio two-photon coupling configuration
Authors: Zhang Lian-Shui  , Li Xiao-Li  , Wang Jian  , Yang Li-Jun  , Feng Xiao-Min  , Li Xiao-Wei  , Fu Guang-Sheng  ,   河北大学物理科学与技术学院，保定  071002
Published: December 2020

Electromagnetically induced transparency (EIT) resonance is obtained in a well-studied lambda three level system where an optical coupling field and a probing field interact with two optical transitions. However, both electromagnetically induced absorption (EIA) and EIT can be obtained in a modified quasi-lambda four level system consisting of an optical-radio two-photon coupling field and a probing field. By solving the density matrix equation of motion, a physical account of EIA and EIT is given in terms of a dressed state picture. It can be seen that the optical coupling field in this quasi-lambda four level system has a crucial effect on the forming of EIA and EIT. An EIA is observed under a resonant optical coupling and it evolves into an EIT when there is a detuning. Furthermore, the width of EIA or EIT increases as the optical coupling Rabi frequency increases.
Experimental schemes for developing fiber-based source of entangled photon pairs
Authors: Yang Lei  , Li Xiao-Ying  , Wang Bao-Shan  ,   天津大学精密仪器与光电子工程学院，光电信息技术科学教育部重点实验室，天津  300072
Published: December 2020

Based on the theory of third-order nonlinear Kerr effect in optical fiber, we experimentally demonstrate the generation of photon pairs by exploiting spontaneous four-wave mixing. The photon pairs are produced by pumping a fiber Sagnac loop and a piece of straight fiber with a pulsed laser, respectively. By comparing the experimental results, we analyze how to optimize the experimental parameters to obtain entangled photon pairs with high purity. Our results are useful for developing the all-fiber source of photon pairs and single photon source, which are well suited for quantum communication.
One-dimensional periodic nanocrystalline silicon arrays made by pulsed laser interference crystallization
Authors: Yao Yao  , Fang Zhong-Hui  , Zhou Jiang  , Li Wei  , Ma Zhong-Yuan  , Xu Jun  , Huang Xin-Fan  , Chen Kun-Ji  , Yasuyuki Miyamoto  , Shunri Oda  ,   (1)东京工业大学物理电子学系，日本东京  152-8552; (2)南京大学物理系，固体微结构物理国家重点实验室，南京  210093
Published: December 2020

One-dimensional periodic nanocrystalline silicon (nc-Si) arrays were fabricated by laser interference crystallization combined with one-dimensional phase shifting grating mask (PSGM). The laser energy density irradiated on the surface of samples with different thicknesses of a-Si:H can be modulated by the PSGM with periodicity of 400 nm. Raman spectra confirmed the crystallization of the irradiated stripe-patterned area of the samples. The transmission electron microscopic and atomic force microscopic images demonstrate that the periodicity of one-dimensional nc-Si arrays is the same as that of the PSGM. And by controlling the laser energy density, a stripe width of 30 nm in each period was obtained as the thickness of a-Si:H decreased from 10 to 4 nm. The high resolution transmission electron microscope images show the clear crystalline lattice of nc-Si within the stripe patterns.
Parameter identification of gas bubble model in pressure pulsations using genetic algorithms
Authors: Jiang Dan  , Li Song-Jing  , Bao Gang  ,   哈尔滨工业大学流体控制及自动化系,哈尔滨  150001
Published: December 2020

Pressure changes in the flowing fluid result in the growth and collapse of gas bubbles and cavitation, which affects the fluid flowing and pressure. In order to predict gas bubble and cavitation volume change during the pressure pulsations in fluid control system and their effects on the pulsations, a mathematical model of gas bubble and cavitation is studied based on gas bubble resolving and releasing physical processes. The method using genetic algorithms (GAs) in parameter identification for the gas bubble model is presented, including the parameters of initial gas bubble volume, gas resolving time constant and releasing time constant. An example of pressure transients accompanying gas bubble and cavitation inside the hydraulic pipeline is simulated and tested. According to the simulation and experimental results, the feasibility of parameter identification for gas bubble model using GAs is verified.
Numerical simulation of particle species behavior in atmosphere plasmas with different ionization degree
Authors: Pang Xue-Xia  , Deng Ze-Chao  , Dong Li-Fang  ,   河北大学物理科学与技术学院，保定  071002
Published: December 2020

A zero-dimensional model is used for studying the behavior of main particle species in atmosphere plasmas with different ionization degrees. The electron lifetimes are obtained for different initial density in an afterglow plasma, and the temporal evolutions of the main charged and neutral species are presented. The results show that the electron number density decays fast, and the lifetimes decrease with ionization degree increasing. Some important neutral species such as O, N, O3 and NO are also analyzed with ionization degree increasing.
Experimental study of optical radiation of hot electrons transport in targets at the rear-side radiation
Authors: Wang Guang-Chang  , Zheng Zhi-Jian  , Gu Yu-Qiu  , Wen Xian-Lun  , Chen Tao  , Zhang Ting  , Zhang Jian-Wei  ,   (1)成都医学院信息管理学院,成都  610083; (2)成都医学院信息管理学院,成都  610083；中国工程物理研究院激光聚变研究中心，绵阳  621900; (3)中国工程物理研究院激光聚变研究中心，绵阳  621900
Published: December 2020

This paper reports the image pattern of spatial distribution and spectrum of optical radiation measured in the normal direction from the rear side of the target employing optical CCD camera and optical multi-channel analysor on the 100 TW femtosecond laser facility. The image pattern of spatial distribution has a ring-shape, the region of optical radiation has larger radiation angle and optical intensity distribution, and the radiation is comprised of many components. The spectrum of optical radiation shows a sharp peak near 800nm, which is attributed to the laser fundamental (ω0), and is ascribed to the coherent transition radiation (CTR) generated by microbunches of hot electron beams generated in transport. With the increase of the laser energy, the peak of the CTR moves further to the long wavelength side, the red shift is caused by the expansion of the critical density surface. The acceleration of hot electron comes mainly from resonance absorption.
Epitaxial growth and mechanical properties of AlN/Si3N4 nanostructured multilayers
Authors: Yu Li-Hua  , Dong Song-Tao  , Dong Shi-Run  , Xu Jun-Hua  ,   江苏科技大学材料科学与工程学院，江苏省先进焊接技术重点实验室，镇江  212003
Published: December 2020

Monolithic AlN，Si3N4 films and AlN/Si3N4 multilayers with different modulation periods were prepared by reactively magnetic sputtering. The films were characterized by X-ray diffraction, high-resolution transmission electron microscopy and nanoindentation. The results showed that the crystal structure of Si3N4 layers in the multilayers and the hardness of AlN/Si3N4 multilayers depend on the thickness of Si3N4 layer. When the thickness of AlN is 4.0nm and that of Si3N4 layer is 0.4nm, Si3N4 layers grew epitaxially with AlN and form strong columnar crystals which extend over several modulation periods. A large degree of hardness enhancement of the multilayer was produced. The microstructure of Si3N4 changes from crystalline to amorphous as Si3N4 thickness increases, leading to blocking of the epitaxial growth and the superhardness effect disappears. The critical thickness of Si3N4 layers, which marks the change from crystalline to amorphous, has been calculated through thermodynamic and elastic considerations. The hardening mechanisms of AlN/Si3N4 multilayers are discussed.
The reaction sequence of lithiation in Mg2Ge and the changes of its electronic structure
Authors: Liu Hui-Ying  , Zhu Zi-Zhong  , Yang Yong  ,   (1)集美大学物理系，厦门  361021; (2)厦门大学固体表面物理化学国家重点实验室，厦门  361005; (3)厦门大学物理系，厦门  361005
Published: December 2020

Mg2Ge is a promising new anode material for lithium ion batteries. The ab initio pseudopotential method with the plane wave expansion of the crystal wave function was employed to study the lithiation properties of anode material Mg2Ge. The reaction sequence of lithiation in Mg2Ge have been calculated. It was found that Li ions firstly occupy the interstitial sites until the interstitial sites are full, and then substitute the Mg sites until half of the Mg sites are replaced to form the phase of Li2MgGe. The calculation results also show that the crystal volume firstly expands and then shrinks as the number of Li ions increases. The changes of crystal volume are very big during the whole process which is the cause of bad cycle performance of the material. The electronic structures are also analyzed, which indicates that the host material changes from semiconducting to metallic then to semiconducting with the increase of Li intercalations.
Thermoelectric properties of transverse transport in nanowire array structures
Authors: Zhang Yi-Qun  , Shi Yi  , Pu Lin  , Zhang Rong  , Zheng You-Dou  ,   南京大学物理系，江苏省光电功能材料重点实验室，南京  210093
Published: December 2020

The electronic structures of nanowire-composite arrays are calculated theoretically in the framework of effective-mass envelope function theory，and various coefficients about electronic transport are obtained. At the same time，a closed-form expression based on boundary scattering theory for lattice thermal conductivity is presented. Then the thermoelectric properties of Si nanowire/Ge host material are investigated as function of the Fermi energy，wire diameter and separation between nanowire sidewalls. The results show that the ZT value of nanowire-composite can be significantly increased by carefully adjusting the correlative parameters of the structure.
Dynamical study on charge injection and transport in a metal/poly(p-phenylene vinylene)/metal structure
Authors: Li Dong-Mei  , Li Hai-Hong  , Li Yuan  , Liu De-Sheng  , Xie Shi-Jie  ,   (1)山东大学物理学院，济南  250100; (2)山东大学物理学院，济南  250100；山东大学晶体材料国家重点实验室，济南  250100; (3)山东大学物理学院，济南  250100；山东大学晶体材料国家重点实验室，济南  250100；济宁学院物理系，曲阜  273155
Published: December 2020

On the basis of the tight-binding Su-Schrieffer-Heeger model， the dynamical process of charge injection from metal electrode to a polymer in a metal/poly(p-phenylene vinylene) (PPV)/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PPV. The formation of the wave packet sensitively depends on the applied voltage， the electric field， and the contact between PPV and the metal electrode. In the absence of external fields， the charge can be injected into PPV chain and form wave packet under the critical bias voltage. With the increase of the electric field， the charge carriers can be ejected from PPV to the right metal electrode. But when the electric field becomes high enough， the wave packet can not be formed because it moves too fast in PPV. It is also shown that the number of ejected charges is not an integral multiple of the elementary charge e.
Effects of external magnetic field on the effective g factor of (Ga，Mn)As
Authors: Zhou Rong  , Sun Bao-Quan  , Ruan Xue-Zhong  , Gan Hua-Dong  , Ji Yang  , Wang Wei-Zhu  , Zhao Jian-Hua  ,   中国科学院半导体研究所超晶格与微结构国家重点实验室，北京  100083
Published: December 2020

With the help of time resolved magneto-optic Kerr rotation measurements， the optically induced spin precession in heavily doped diluted magnetic semiconductor Ga0.937Mn0.063As was observed. It was found that the effective g factor increases with increasing magnetic field， which is attributed to the magnetic-field-induced increase of the density of the non-localized holes. Those free holes will couple with the localized magnetic ions by p-d interactions， leading to the formation of spontaneous magnetization in Ga0.937Mn0.063As， which in turn to the enhancement of the effective g factor.
Raman scattering study of the spin ladder compound Sr14(Cu1-yFey)24O41
Authors: Hu Ni  , Xiong Rui  , Wei Wei  , Wang Zi-Yu  , Wang Li-Li  , Yu Zu-Xing  , Tang Wu-Feng  , Shi Jing  ,   (1)湖北工业大学理学院，武汉  430068；武汉大学物理系，教育部声光材料与器件重点实验室，武汉  430072; (2)武汉大学物理系，教育部声光材料与器件重点实验室，武汉  430072
Published: December 2020

Serials of spin ladder compound Sr14(Cu1-yFey)24O41 with different doping level have been prepared by conventional solid state reaction method. The polarized Raman spectroscopy shows the existence of (4Ag+4B1g+3B2g+B3g) modes， and the peak at 1170 cm-1 for all the samples are associated with the longitudinal phonon mode which reveals the information of the ladder. Furthermore， we have compared the result of the Raman spectroscopy with the conduction behavior.
The research on long range correlation of Lorenz system
Authors: Wang Qi-Guang  , Zhi Rong  , Zhang Zeng-Ping  ,   (1)兰州大学大气科学学院，兰州  730000；国家气候中心，中国气象局气候研究开放实验室，北京  100081; (2)扬州大学物理科学与技术学院，扬州  225002；国家气候中心，中国气象局气候研究开放实验室，北京  100081; (3)扬州大学物理科学与技术学院，扬州  225002；中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029
Published: December 2020

This paper takes the typical chaotic system， the Lorenz system， as the subject. We use the detrended fluctuation analysis method to study the systems long-range correlation for different initial values and parameters. It turns out that the systems long range correlation is related with its initial values phase space position. When the initial value is close to the unstable equilibrium points， the systems long rang correlation is strengthened， the scaling exponents α are bigger， and the predictability of the system is better. When the system is in complete chaotic state， its long range correlation becomes weak with the parameters increasing， and the scaling exponents α are decrease， the predictability of the system becomes weaker. This reveals the relationship between the systems long range correlation and its predictability. We disturbed the system equation with random noise and found that the systems long range correlation decreases with the increase of random noise intensity. This result further signifies out that the Lorenz system's long range correlation is a physical parameter that may serves as an effective predictability criterion.
Analysis of dynamical statistical characteristics of temperature correlation networks of 1—30d scales
Authors: Gong Zhi-Qiang  , Zhou Lei  , Zhi Rong  , Feng Guo-Lin  ,   (1)国家气候中心，中国气象局气候研究开放实验室，北京  100081；兰州大学大气科学学院，兰州  730000; (2)扬州大学物理科学与技术学院，扬州  225002; (3)扬州大学物理科学与技术学院，扬州  225002；国家气候中心，中国气象局气候研究开放实验室，北京  100081; (4)中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029；国家气候中心，中国气象局气候研究开放实验室，北京  100081
Published: December 2020

Based on reanalysis data of National Center of Environment Prediction of America， temperature correlation networks of different time scales are constructed and their dynamical statistical properties are also analyzed. Results show that temperature correlation networks of 1 and 30d belong to small world and semi-globally coupled network， respectively. The time scale condition is 11—12d for networks to shift from one type to the other. For 1 d scale， the total number of links at each geographic location is semi-symmetrical between north and south hemisphere， the equatorial nodes have a larger number of connections in three regions: the equatorial Indian ocean， equatorial east Pacific ocean and equatorialeast Atlantic ocean. Sub-system networks of both mid-latitude and low-latitude belong to the small world network， while the accumulative degree distribution of low-latitude follows the exponentical and Gaussian distributions and that of mid-latitude follows the semi-Gaussian distribution. The range of correlation condition value for temperature network belonging to small world network is 0.2—0.9. Meanwhile for the 30 d scale， ocean nodes show a larger number of connections than the land nodes. The ocean and the land sub-system networks belong to the semi-globally coupled and the small world networks， respectively. The range of correlation condition value for temperature network belonging to semi-globally coupled network is 0—0.6.
A new periodic wave solution for the (2+1)-dimensional Boussinesq equation
Authors: Wu Yong-Qi  ,   湛江师范学院数学系，湛江  524048
Published: December 2020

The new periodic wave solution for the (2+1)-dimensional Boussinesq equation is presented by using of Hirota method and Riemann theta function, from which the soliton solution can be obtained via an appropriate limited procedure.
Ture random number generators based on mouse movement and chaos systems
Authors: Zhou Qing  , Hu Yue  , Liao Xiao-Feng  ,   重庆大学计算机学院，重庆  400030
Published: December 2020

True random number generator (TRNG) is usually more secure than pseudo-random number generator.In this paper,a novel TRNG which produces random bits by noving the mouse casually is proposed which is cheap,convenient and universal for personal computer (PC) platforms.To eliminate the patterns among mouse movements of the same user,two approaches based on image encryption algorithm and Hash function were poposed,both making use of the sensitivity of chaos system.Abundant random bits generated by three users were tested strictly using U.S. NIST’s 16 statistical tests.All TRNGs passed the test successfully,and the revised TRNG is believed to be applicable practically on PC platforms.
Research on the evolution process of virtual community networks
Authors: Zhang Li  , Liu Yun  ,   北京交通大学通信与信息系统北京市重点实验室，北京  100044
Published: December 2020

We investigate and simulate the evolution process and topological features of the virtual community networks.We founded that the joint of nodes, joint of edges, networks’ degree distribution, average degree and the correlation between the node’s degree and its time in the network are different from the scale-free network model.With statistics and analysis of some of the characteristics of an actual Internet forum, we propose a new network evolution algorithm, namely the virtual community network construction algorithm.The simulation results show that the networks generated from our algorithm has the same characteristics as the real virtual community networks.
The effect of strong magnetic field on proton branch of modified URCA process
Authors: Zhang Jie  , Liu Men-Quan  , Wei Bing-Tao  , Luo Zhi-Quan  ,   (1)西华师范大学理论物理研究所，南充  637002; (2)中国科学院国家天文台/云南天文台,昆明  650011；中国科学院研究生院,北京  100049
Published: December 2020

The neutrino energy loss rate of modified URCA process in strong magnetic field of neutron star core is investigated based on the n-p-e model. Both neutron and proton branches of modified URCA process are considered. The result shows that a strong magnetic field makes the neutrino energy loss rate of modified URCA process to oscillate intensively. Compared with the neutron branch, neutrino energy loss rate of the proton branch is weaker. But the total neutrino energy loss rate will increase due to the proton branch of modified URCA processes. The result will contribute to the research of cooling mechanism of neutron stars.
Transmission characteristics of a rectangular waveguide filled with anisotropic metamaterial
Authors: Meng Fan-Yi  , Wu Qun  , Fu Jia-Hui  , Yang Guo-Hui  ,   哈尔滨工业大学电子与信息技术研究院，哈尔滨  150001
Published: December 2020

The effective permittivity, effective permeability and the phase factor of a rectangular waveguide filled with an anisotropic metamaterial is derived through solving the wave equation. A group of important conclusions is obtained through discussing the relations between transmission characteristics of the waveguide and constitutive parameters of the filling metamaterial. It is shown that characteristics of the waveguide are determined by the transversal constitutive parameters when the operating frequency is higher than the cut_off frequency, and they are independent on the longitudinal constitutive parameters. However, below the cut off frequency, the characteristics of the waveguide are determined by both the transversal and longitudinal constitutive parameters. Two examples are calculated to demonstrate the above conclusions, and it is shown that calculated results are in a good agreement with the theoretical predictions. These results play important role in the applications of metamaterials to waveguide.
Generation of C-NOT gate, swap gate and phase gate based on a two-dimensional ion trap
Authors: Ai Ling-Yan  , Yang Jian  , Zhang Zhi-Ming  ,   华南师范大学信息光电子科技学院，光子信息技术广东省高校重点实验室，广州  510006
Published: December 2020

We study the realization of quantum logic gates in the interacting system of a two-dimensional trapped ion and two laser beams. We simplify the Hamiltonian of the system by Choosing the frequency detuning of laser fields and the transition frequency between the internal states of the ion, and furthermore，we describe the realization of a C-NOT gate, a swap gate and a phase gate. During these processes, the system needs to meet the Lamb-Dicke limit, and the Rabi oscillation frequency should be far smaller than the phonon frequency.
Measurement of quantum states with incoherent light
Authors: Ma Rui-Qiong  , Li Yong-Fang  , Shi Jian  ,   (1)陕西师范大学物理学与信息技术学院,西安  710062; (2)西安邮电学院电子与信息工程系,西安  710061
Published: December 2020

A novel and high resolution method for measuring quantum states with incoherent light in the time-domain is presented. Taking Autler-Townes effect as an example, the physical process and the evolution rule during measurement are discussed by an explicit analytical formulation in detail; and the influence of measuring process on the quantum state is disclosed. With this method, very small splitting of the energy-level and large energy-level space can be measured readily at the same time, while the transverse relaxation rate of the system can be obtained directly by checking the decay time of the signal. Compared with the characteristics of the measuring methods between the time-domain and frequency-domain, we found that the measuring quantum states with incoherent light in the time-domain is robust and valid for disclosing information of the quantum state completely.
Experimental quantum key distribution with double protocol
Authors: Hu Hua-Peng  , Zhang Jing  , Wang Jin-Dong  , Huang Yu-Xian  , Lu Yi-Qun  , Liu Song-Hao  , Lu Wei  ,   (1)华南师范大学信息光电子科技学院,光子信息技术广东省高校重点实验室,广州  510006; (2)中国科学院合肥智能研究所，合肥  230031
Published: December 2020

We propose one kind of improved QKD scheme based on time coding and phase coding. The pulse which had been discarded on the BB84 protocol phase coding QKD system is used to realize the time coding protocol, thus the useful bits rate in the present scheme can be doubled. At the same time, the phase coding keys and the time coding keys are obtained, we may combine both as new keys which can enhancethe generated rate and the sensitivity of monitor. At Bob’s side, a Fraday-Michelson is used instead of a traditional M-Z interferometer, which improves the stability of the interference visibility. With the proposed experimental setup, a stable quantum key distribution was performed over 90 km fiber. It is shown in our experiment that the characteristics of our system are as follows: secure, stable and economical.
A new circuit model for avalanche photodiodes to detect infrared single photon by transient process of transmission lines
Authors: Wang Jin-Dong  , Wu Zu-Heng  , Zhang Bing  , Wei Zheng-Jun  , Liao Chang-Jun  , Liu Song-Hao  ,   华南师范大学信息光电子科技学院光子信息技术广东省高校重点实验室，广州  510631
Published: December 2020

A new circuit model for using the avalanche photodiodes to detect infrared single photon is proposed, which combines the requirements of a single photon detector control circuit and features of the electric pulses generator by transient process of transmission lines. The simulation results are given for the new circuit model and the emphasis is laid on the analysis of the feasibility of the circuit model in using the gate mode scheme of the avalanche photodiodes to detect infrared single photon and the influence of each electrical component on the performance of the circuit model. Finally, optimal parameters of the electrical components and the gate-mode with the quenching circuit model are demonstrated.
Investigation of propagation of spatial soliton in nonlocal nonlinear medium of finite-size
Authors: Liang Yan-Bin  , Zheng Ya-Jian  , Yang Ping-Bao  , Cao Long-Gui  , Lu Da-Quan  , Hu Wei  , Guo Qi  ,   华南师范大学光子信息技术广东省高校重点实验室，广州  510006
Published: December 2020

In this paper, we investigate the effect of the boundary of the nonlocal nonlinear medium on the propagation of soliton. On the basic of NNLSE and the Poisson equation, using the Green function approach, we obtain the response function of the lead glass of finite-size, which is a strong nonlocal medium. Starting with the paraxial ray equation, we obtain the analytical solutions of the oscillation trajectory and period of the beam. Comparing the analytical solutions with numerical simulations, we found that our analytical solutions are precise when the point of incidence is not near the boundary of the medium.
Investigation on up-conversion luminescence of Tm3+ and Yb3+ codoped oxy-fluorosilicate glass ceramics
Authors: Gan Zong-Song  , Yu Hua  , Li Yan-Ming  , Wang Ya-Nan  , Chen Hui  , Zhao Li-Juan  ,   南开大学物理科学学院光子学中心，天津  300071，弱光非线性光子学教育部重点实验室(南开大学)，天津市信息光子材料与技术重点实验室，天津  300457
Published: December 2020

Two series of Tm3+ and Yb3+codoped oxy-fluorosilicate glass ceramics with the composition of 30SiO2-(20-x-y)Al2O3-40PbF2-10CdF2-xTm2O3-yYb2O3 were prepared and characterized. The up-conversion spectra of the samples were investigated and the up-conversion luminescence mechanisms of Tm3+/Yb3+ system were analyzed. The effects of Tm3+ and Yb3+ concentration on up-conversion luminescence spectra weresystematically studied. The results suggest that blue up-conversion emission intensity decreases when Tm3+ concentration increases due to the cross relaxation interaction between Tm3+ ions. The optimum Tm3+ concentration is 0.025mol%. Three-photon process and Yb3+ ion cooperative up-conversion energy transfer process co-exist in the Tm3+/Yb3+ up-conversion luminescence system. When Yb3+ concentration increases, due to the energy back-transfer process of 3H4(Tm3+)→2F5/2(Yb3+), the blue up-conversion emission intensity would decrease. With the help of Yb3+ ion cooperative up-conversion energy transfer, the blue up-conversion emission intensity actually increases, which is in accordance with the experimental results.
Investigation of broadband solid state dye laser based on PM580 doped PMMA
Authors: Fan Rong-Wei  , Xia Yuan-Qin  , Li Xiao-Hui  , Jiang Yu-Gang  , Chen De-Ying  ,   哈尔滨工业大学光电子技术研究所，哈尔滨  150001
Published: December 2020

As solid-state dye lasers exhibit the attractive features of compactness， being intoxic, and low cost, the development of tunable solid-state dye lasers is an area of active research. Solid state dyes based on polymethyl methacylate (PMMA) doped with new high efficiency pyrromethene-580 were prepared. First, the absorption and fluorescence of the samples were obtained. Pumped by the second harmonic of Q switched Nd:YAG laser, the output characteristics of the solid state dye lasers with different dye concentrations were studied. The central wavelength of the lasing emission peak increases with increasing dye concentration. The slope efficiencies of the samples were also obtained. The highest slope efficiency of 53.8% was obtained with dye concentration of about 2×10－4 mol/L. Pumped at 410mJ, the pulse energy of the solid dye laser reached 220mJ with the band width～8nm.
New far-field detection technique for beam alignment system in high power laser facility
Authors: Ding Li  , Liu Dai-Zhong  , Gao Yan-Qi  , Zhu Bao-Qiang  , Zhu Jian  , Peng Zeng-Yun  , Zhu Jian-Qiang  , Yu Li-Jun  ,   (1)上海大学机械制造及其自动化学院，上海  200072; (2)中国科学院上海光学精密机械研究所高功率装置物理联合实验室，上海  201800
Published: December 2020

The laser beam automatic alignment system is applied to a high power laser facility for inertial confinement fusion. The far-field detection is a key technique of the automatic alignment system. Utilizing the image of spatial filter’s pinhole of the high power laser system and diffraction of sampling grating, a new method for far-field detection of laser beam is proposed and fully demonstrated on the experimental system. The experimental results indicate that, unlike the traditional method, this far-field detection system can fully use the space through off-axial grating sampling, and the average far-field alignment error is less than 0.9% of spatial filter pinhole diameter, which meets the alignment system requirements of less than 5% of spatial filter pinhole diameter.
An acoustic gas concentration measurement algorithm for carbon monoxide in mixtures based on molecular multi-relaxation model
Authors: Zhu Ming  , Wang Shu  , Wang Shu-Tao  , Xia Dong-Hai  ,   华中科技大学电子与信息工程系，武汉  430074
Published: December 2020

In this paper，we disclose the relations between multi-relaxation absorption and the acoustic parameters when ultrasound propagates in gas mixtures，such as the relation between concentrations of constituents and acoustic frequencies. In the meantime，the dependence of acoustic velocity on the same parameters is discussed. Based on the sample consisting of carbon monoxide，water vapor，nitrogen and oxygen，we establish the three dimensional model for the relation between concentrations of mixture constituents and relaxation absorption and acoustic velocity，respectively. Further more，we give the two dimensional dependence between relaxation absorption and acoustic frequency. We propose a simplified algorithm to calculate the carbon monoxide concentration by measuring the relaxation absorption and acoustic velocity. Simulation results proved the feasibility of this method and showed the appropriate range of acoustic frequency. The origins of errors arising in the application of the method are indicated in this paper.
Introduction of 6-band P-1 radiation model for numerical analysis of three-dimensional air arc plasma
Authors: Wu Yi  , Rong Ming-Zhe  , Yang Fei  , Wang Xiao-Hua  , Ma Qiang  , Wang Wei-Zong  ,   西安交通大学电力设备电气绝缘国家重点实验室，西安  710049
Published: December 2020

6-band P-1 radiation model is introduced to implement the simulation of three-dimensional air arc plasma. The calculation has the specific feature that both radiation emission and self-absorption are taken into account. The distributions of temperature and radiation flux density are obtained and analyzed. Comparing with the net emission coefficient (NEC) method，its temperature distribution range is wider and the arc column voltage is more close to the experimental test value，which shows that the P-1 model can be used to solve the arc radiation problem more accurately.
First-principle study of N，Ga codoped p-type ZnO
Authors: Zhao Hui-Fang  , Cao Quan-Xi  , Li Jian-Tao  ,   西安电子科技大学技术物理学院，西安  710071
Published: December 2020

The geometric structure，band structure and density of state of pure and N-Ga，2N-Ga codoped wurtzite ZnO have been investigated by first-principles ultrasoft pseudopotential method in the generalized gradient approximation. The calculation results show that the codoped structure N-Ga has better stability. Our work indicates that，the carrier concentration is increased in the 2N-Ga codoped configuration where the delocalized features are obvious，and this structure is more in favor of the formation of p-type ZnO.
Investigation of the UV absorption of porous TiO2/Al/SiO2 nanostructures
Authors: Ma Bao-Hong  , Li Yan  , Wang Cheng-Wei  , Wang Jian  , Chen Jian-Biao  , Liu Wei-Min  ,   (1)西北师范大学物理与电子工程学院，兰州  730070; (2)西北师范大学物理与电子工程学院，兰州  730070；中国科学院兰州化学物理研究所固体润滑国家重点实验室，兰州  730000; (3)中国科学院兰州化学物理研究所固体润滑国家重点实验室，兰州  730000
Published: December 2020

The porous TiO2/SiO2 and TiO2/Al/SiO2 nanostructures are successfully fabricated by anodic oxidation of titanium or titanium/aluminum thin films deposited on transparent SiO2 glass substrates with pulsed laser deposition (PLD) technique. The optically transparent titania films, with highly ordered and uniformly arrayed pores are characterized by field emission scanning electron microscope (FESEM). The influence of Al buffer layer on the optical absorption of the porous TiO2 thin films was investigated. The results show that without Al buffer layer the UV absorption peak of the porous TiO2 films was fixed at 270nm and the intensity of absorption peak was not modulated by the anodic potential. However, with an Al buffer layer, the UV absorption peak will shift to 293nm, and the intensity of absorption peak was not only modulated by anodic potential, but also sensitively influenced by the thickness of Al buffer layer. Moreover, the optical transition property of the two nanostructures at the absorption edge was analysed.
Fabrication and I-V characteristics of ZnO nanowire-based field effect transistors
Authors: Zhang Wei  , Li Meng-Ke  , Wei Qiang  , Cao Lu  , Yang Zhi  , Qiao Shuang-Shuang  ,   (1)大连理工大学物理与光电工程学院，大连  116024; (2)兰州大学化学系，兰州  730000; (3)辽宁师范大学物理与电子技术学院，大连  116029
Published: December 2020

The ZnO nanowire-based insulation gate field effect transistors were fabricated by connecting single ZnO nanowires across three kinds of symmetrical metal trenches (Au, Zn and Al thin films) with different widths. In the testing processes, the traditional ion beam eroding technology, electronic probe, and atom force microscopy probe methods were employed. The I-V characteristics of various synthesized ZnO nanowire-based devices were researched. The results showed that the main effecting factor on the I-V characteristic is the type of contact between the ZnO nanowire and the surface of different trenches, which may be of the Ohmic or the Schottky contact type in different cases. Finally, the I-V characteristics of the fabricated devices had been discussed by using the electron transport mechanism.
Surface plasmon polariton modulator based on electro-optic polymer
Authors: Chen Jian-Jun  , Li Zhi  , Zhang Jia-Sen  , Gong Qi-Huang  ,   北京大学物理系,人工微结构和介观物理国家重点实验室，北京  100871
Published: December 2020

A simple, high efficiency and mini-sized surface plasmon polariton (SPP) modulator based on electro-optic polymer is proposed. The modulator is constructed by metallic stripes of Mach-Zender (M-Z) interferometric structure and with electro-optic polymer surrounding the stripes. The reflectivity index of the electro-optic polymer is modulated when the modulating voltage is applied to the two arms of the M-Z interferometer. Through the M-Z interferometer, the modulation of the reflectivity index can be transferred into the modulation of the SPP intensity. By calculating the electric field near the metallic stripes and taking the distribution of SPP field into account, the working principle of the SPP modulator is demonstrated in detail and the half-wave modulating voltage is evaluated as 2.8V.
Spin-polarized transport in ferromagnetic semiconductor/ferromagnetic d-wave superconductor tunnel junction
Authors: Dong Zheng-Chao  ,   淮阴师范学院物理系，淮安  223001
Published: December 2020

By solving a self-consistent equation for the d-wave superconducting gap and the magnetization, and applying an extended Blonder-Tinkham-Klapwijk approach, we study the spin-polarized quasiparticle transport coefficients and the differential conductance in ferromagnetic semiconductor/ferromagnetic d-wave superconductor junction. It is shown that (1) the exchange energy h0 in the ferromagnetic d-wave superconductor may make the zero-bias conductance peak and energy gap peak split into two peaks, and the energy difference between the two splitting peaks is equal to 2h0; (2) the exchange energy　hFS in the ferromagnetic semiconductor can decrease the height of the two peaks resulting from splitting of the zero-bias conductance peak. For the splitting of the energy gap conductance peak, however, with hFS increased the left-hand peak is lowered and the right-hand peak is raised in the parallel configuration, but the left-hand peak is raised and the right-hand peak is lowered in the antiparallel configuration.
Study of the XY chain with long-range interactions
Authors: Li Jia-Liang  , Lei Shu-Guo  ,   (1)常熟理工学院江苏省新型功能材料重点建设实验室,常熟  215500；常熟理工学院物理与电子科学系，常熟  215500; (2)南京工业大学应用物理系，南京  210009
Published: December 2020

Using the mean-field Jordan-Wigner transformation analysis, we have studied the one-dimensional spin-1/2 XY chain with Z-directional uniform long-range interactions in the external magnetic field. We have obtained such results as the Helmholtz free energy, internal energy, specific heat, magnetization and isothermal susceptibility. We also discuss the first and second-order phase transitions of the system at a finite temperature. Our results agree with results published in literature.
Single magnetic field-driven magnetoelectric effect in Tb1-xDyxFe2－y/Pb(Zr, Ti)O3 laminate composites
Authors: Yin Xiao-Ming  , Zhang Ning  ,   南京师范大学磁电子学实验室,南京  210097
Published: December 2020

In this paper we discuss the preparation of Tb1-xDyxFe2－y/Pb(Zr,Ti)O3 trilayers and a technique of single magnetic field-driven magnetoelectric coupling. A colossal ME voltage has been measured in the trilayers with the technique. The results obtained are far from that observed from that driven by two-field ME effect for the same material and probably predict some new physical effect. This technique can be expected to simplify the applications of ME effect in some fields.
Multi-exponential inversion of T2 spectrum in NMR based on differential evolution algorithm
Authors: Pan Ke-Jia  , Chen Hua  , Tan Yong-Ji  ,   (1)复旦大学数学科学学院，上海  200433; (2)中国石油大学(华东),东营  257061
Published: December 2020

A new multi-exponential inversion method for NMR relaxation signals is presented and tested, which is based on differential evolution (DE) algorithm. The inversion of T2 spectrum in NMR is reduced to a non-negative constraint optimization problem, and solved directly by DE algorithm without pre-assigning the distribution of relaxation time T2. The validity and effectiveness of our method is demonstrated by computer simulations and the inversion of practical NMR data under low SNR.
Negative capacitance in polymer light-emitting diodes
Authors: Huang Wen-Bo  , Zeng Wen-Jin  , Wang Li  , Peng Jun-Biao  ,   (1)华南理工大学聚合物光电材料及器件研究所，广州  510640; (2)华南理工大学聚合物光电材料及器件研究所，广州  510640；华南理工大学特种功能材料及其制备新技术教育部重点实验室,广州  510640
Published: December 2020

A.c. electrical properties of the heterostructured polymer light-emitting diode consisting of poly［2-methoxy-5-(2′-ethyl-hexyloxy)- 1, 4-phenylenevinylene］(MEH-PPV) as the light-emitting layer, and poly［(9,9 - bis(3′-(N,N-dimethylamino) propyl)-2,7- fluorene)-alt-2,7-(9,9-dioctylfluorene)］ (PF-NR2) as the electron-injecting layer, are studied by using impedance spectroscopy. Negative capacitance in impedance spectroscopic data has been observed. According to the Cole-Cole plot of the device ITO/PEDOT/MEH-PPV/PF-NR2/Al, the a.c. response of MEH-PPV/PF-NR2 interface can be explained in terms of the equivalent circuit model of a parallel combination of an inductance L and a resistance RL. The experiments showed that PF-NR2 could act as an electron injecting and hole blocking layer. We propose an energy band structure schematic diagram to explain the enhancement of the EL efficiency in the ITO/PEDOT/MEH-PPV/PF-NR2/Al structure.
Study of the growth characteristics of SiCGe layers grown on 6H-SiC substrates
Authors: Lin Tao  , Chen Zhi-Ming  , Li Jia  , Li Lian-Bi  , Li Qing-Min  , Pu Hong-Bin  ,   西安理工大学电子工程系，西安  710048
Published: December 2020

SiCGe layers were grown on 6H-SiC (0001) substrates by low pressure hot wall chemical vapor deposition at different temperatures (1100℃—1250℃) and with different GeH4 flow-rate ratios (6.3%—25%). Surface morphology, growth characteristics, and Ge contents of the samples were studied. Results of scan electron microscope images show that the SiCGe layers tend to grow in an island growth mode at lower temperatures, and the growth mode will change to the layer by layer mode accompanied by changes in island form and density as the growth temperature increases. X-ray photoelectron spectroscopy tests show that the Ge contents in the samples are in a range of 0.15％ to 0.62％, and they increase with the increase of GeH4 flow rates and the decrease of growth temperatures when other growth parameters are kept constant. Additionally, antiphase boundary (APB) defects in the SiCGe layers were analyzed qualitatively.
Influence of annealing on structure and optical band gap of nitrogen doping fluorinated amorphous carbon films
Authors: Jiang Ai-Hua  , Xiao Jian-Rong  , Wang De-An  ,   桂林工学院数理系，桂林  541004
Published: December 2020

Radio frequency plasma enhance chemical vapor deposition (RF-PECVD) was used todeposit nitrogen doped fluorinated amorphous carbon (a -C:F,N) films with CF4, CH4 and N2 as source gases. We focused on the influence of annealing temperature on the structure and optical band gap (Eg) of the films. The as-deposited films undergo significant chemical and optical changes during annealing. The films are thermally stable at 350℃. The optical band gap shows decrease of different degrees with increasing annealing temperature. Raman and Fourier transform infrared absorption spectra show that the relative content of F in the films decreased, while the content of sp2 carbon increased, and as a result, the density of states near the band edgye of σ-σ* decreases, which is responsible for the increasing Eg.
Discussion on backscattered photon numbers and their scattering events in a turbid media
Authors: Xu Lan-Qing  , Li Hui  , Xiao Zheng-Ying  ,   福建师范大学医学光电科学与技术教育部重点实验室，福州  350007
Published: December 2020

Due to strong scattering, most optical tomography techniques can’t achieve practical imaging depth in turbid media such as bio-tissues. In this paper a new inner-light-source model was proposed and Monte Carlo method was used to analyze related problems. The distribution of backscattered photon number against the number of their scattering events was studied, and various illumination geometries and detecting methods were simulated. The results show that instead of rashly assuming that the number of photons reemitted from the tissue monotomically increases or decreases as scattering events accumulates; the backscattered photon number actually increases firstly and decreases later. The peak position, peak value and curve shape depend on the illumination geometry, monitoring method and tissue optical parameters.