Integrated Optical Parallel Logic Processor Based on Birefringent Array Illuminator

Ｉｎｔｅｇｒａｔｅｄ　Ｏｐｔｉｃａｌ　Ｐａｒａｌｌｅｌ　Ｌｏｇｉｃ　Ｐｒｏｃｅｓｓｏｒ　Ｂａｓｅｄ　ｏｎ　Ｂｉｒｅｆｒｉｎｇｅｎｔ　Ａｒｒａｙ　ＩｌｌｕｍｉｎａｔｏｒＩｎｔｅｇｒａｔｅｄＯｐｔｉｃａｌＰａｒａｌｌｅｌＬｏｇｉｃＰｒｏｃｅｓｓｏｒＢａｓ...     

Phase Space Prediction Model Based on the Chaotic Attractor

A new prediction technique is proposed for chaotic time series.The usefulness of the technique is that it removes some false neighbouring points which are not suitable for the local estimation of the dynamics systems.We use a feedforward neural network to approximate the local dominant Lyapunov exponent,and choose the neighbouring points by the exponent.The model is tested for the convection amplitude of the Lorenz model,and the results indicate that this prediction technique can improve the prediction of chaotic time series.     

Quantum Key Distribution Network Based on Differential Phase Shift

Using a series of quantum correlated photon pairs, we propose a theoretical scheme for any-to-any multi-user quantum key distribution network based on differential phase shift. The differential phase shift and the different detection time slots ensure the security of our scheme against eavesdropping. We discuss the security under the intercept-resend attack and the source replacement attack.     

Fabrication of Intrinsic Josephson Junctions on BI2Sr2CaCu2O8＋δ Single Crystals with Reproducible Surface Junctions

Intrinsic Josephson junctions on Bi2Sr2CaCu2O8 δ single crystals are successfully fabricated using photolithography and Ar jon milling .Here we discuss the properties of the surface CuO2/metal bilayers and surface junctions prepared with different crystal cleavage conditions and metal film deposition techniques.We show that,by cleaving the crystal at liquid nitrogen temperature in vacuum,the contents of the (interstitial) oxygen in the Bi-O layers become stable upon cleavage,leading to a CuO2/metal bilayer and to surface junctions with reproducible properites,These results can be useful for practical device fabrications as well as for the studies of the contact properties between high Tc superconductors and normal metals.     

The 0–π Phase Transition in Epitaxial NbN/Ni_(60)Cu_(40)/NbN Josephson Junctions

We fabricate high quality superconductor/ferromagnet/superconductor(SFS) Josephson junctions using epitaxial NbN/Ni_(60)Cu_(40)/NbN trilayer heterostructures. Both experimental measurements and theoretical calculations of the ferromagnet layer thickness dependence of the Josephson critical current are performed. We observe the damped oscillation behavior of the critical current as a function of the ferromagnetic layer thickness at 4.2 K,which shows a 0–π phase transition in this type of magnetic Josephson junction. Clear 0– and reverse –0 phase transitions occur around the Ni_(60)Cu_(40) thicknesses of 3.2 and 6.7 nm. Numerical calculations based on the quasi-classical Usadel equation and the Green function fit well with the experimental results. Compared with the dirty limit, the intermediate regime without the dead layer gives better fit for our SFS Josephson junctions because of the epitaxial structure. Both of the 0-and -phase junctions show the ideal magnetic field dependence with a Fraunhofer-like pattern at 4.2 K.     

Spin Polarization Oscillation and Spin-Polarized Diode Based on Graphene Rashba–Strain Double Junctions

We investigate spin-dependent electron transport through graphene-based Rash ba-strain double junctions. It is found that when electrons are injected from left normal graphene region, high spin polarization oscillation is achieved due to the wave-vector-dependent resonant tunneling. The spin polarization is negligible once the incident direction is reversed. Such a remarkable difference arises from pseudogap caused by the Rashba spin-orbit interaction.     

Josephson Tunnel Junctions with an Integral Superconductor–Insulator–Normal Metal Shunt

Physics of the Solid State - This study is devoted to the investigation of tunneling superconductor–insulator–superconductor (SIS) Josephson junctions with a new type of shunt based on...     

Giant Tunneling Magnetoresistance in Spin-Filter Magnetic Tunnel Junctions Based on van der Waals A-Type Antiferromagnet CrSBr

Two-dimensional van der Waals magnetic materials have demonstrated great potential for new-generation high-performance and versatile spintronic devices. Among them, magnetic tunnel junctions(MTJs) based on A-type antiferromagnets, such as CrI₃, possess record-high tunneling magnetoresistance(TMR) because of the spin filter effect of each insulating unit ferromagnetic layer. However, the relatively low working temperature and the instability of the chromium halides hinder applications ...     

Coherent π Electroproduction on the Deuteron

A general analysis of polarization phenomena for coherent pion electroproduction on deuterons is presented. The spin and isospin structures of the γ*+d→d+P⁰ amplitudes (where γ* is a virtual photon) are established and relationships between meson electroproduction on deuterons and on nucleons are given in the framework of the impulse approximation. The reaction e+d→e+d+π⁰ is investigated in detail, for a relatively large value of momentum transfer, 0.5 GeV²≤−k²≤2 GeV², both at threshold and in the region of Δ-isobar excitation. Special attention is devoted to the sensitivity of different contributions to the exclusive cross section for d(e, eπ⁰)d, as the γ*πω form factor or the NN-potential. The predicted k²-dependence of the cross section agrees well with the available experimental data.     

The β Phase of Isotactic Polypropylene in TPVs Based on PP/EPDM

β‐Nucleating agent was added into maleic anhydride (MAH) compatiblized isotactic polypropylene (iPP)/ethylene‐propylene‐diene monomer (EPDM) blend systems, dynamically vulcanized by dicumyl peroxide (DCP). The β phase of iPP formed in TPVs was investigated by means of WAXD, and the effect of DCP content, MAH content and system viscosity on the β phase of iPP was also studied. With increasing DCP content, the MFR values of blend systems increased a little and then decreased, indicating that the DCP content showed a remarkable effect on the system viscosity. Also, with increasing MFR, the β phase content increased first and then decreased, while with increasing MAH content, the β phase content decreased sharply.     

Characteristics of Multiply π Phase shifted Long period Fiber Gratings

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　ＴｈｅＬＰＦＧｉｓａｔｙｐｅｏｆｔｒａｎｓｍｉｓｓｉｏｎｇｒａｔｉｎｇｂａｓｅｄｏｎｔｈｅｐｒｉｎｃｉｐｌｅｏｆｃｏｕｐｌｉｎｇｔｈｅｇｕｉｄｅｄｆｕｎｄａｍｅｎｔａｌｍｏｄｅｔｏｔｈｅｆｏｒｗａｒｄｐｒｏｐａｇａｔｉｎｇｃｌａｄｄｉｎｇｍｏｄｅｓ.ＵｎｌｉｋｅｔｈｅＢｒａｇｇｇｒａｔｉｎｇ ,ｔｈｅｒｅｆｒａｃｔｉｖｅｉｎｄｅｘｐｅｒｔｕｒｂａｔｉｏｎｏｆＬＰＦＧ’ｓｈａｖｅａｍｕｃｈｇｒｅａｔｅｒｐｅｒｉｏｄｉｃｉｔｙｔｈａｎｔｈｅｗａｖｅｌｅｎｇｔｈｏｆｔｈｅｌ…     

Transition from the 0 state to the π state in S-FNF-S Josephson structures

The critical current I _C of S-FNF-S Josephson structures has been calculated as a function of the distance between the superconducting (S) electrodes, L, via the Usadel semiclassical equations for the case of specifying the supercurrent in the direction parallel to the interface between the ferromagnetic (F) and normal (N) films of the composite weak-link region. It has been shown that, owing to the interaction between the F and N films, both the typical decrease scale of the critical current and the period of its oscillations to lengths of the scale ξ_N can be much larger than the respective quantities for the SFS junctions. Moreover, this interaction changes both the magnitude and sign of the critical current. It has been shown that the critical current in a structure with the collinear magnetization vectors of the films can be significantly different from the critical current in a structure with the antiparallel magnetization of the F films.     

Two-Particle Cluster Theory for Biaxial Nematic Phase Based on a Recently Proposed Interaction Potential

Two-particle cluster theory is applied to study the biaxial nematic phase formed by biaxial molecules interacting with a simplified model proposed by Sonnet et al. [Phys. Rev. E 67 （2003） 061701]. For the temperature dependences of the internal energy per particle and of the order parameters, the two-particle theory yields an improved result compared with mean field theory. Concerning the phase diagram, the two-particle theory gives the numerical result in qualitative agreement with the mean field theory.     

Entangled States Based on Two Coherent States 3π/2 out of Phase

Entangled states based on two coherent states 3π/2 out of phase with each other, i.e. ｜α〉 and e^iФ｜-iα〉, as well as on a special state with a relative phase Ф = ｜α｜^2, are constructed. By analysing the amount of entanglement it is evident that entangled states based on this special state can be used as an excellent resource for quantum teleportation. It is also revealed that these entangled states possess some nonclassical features.     

Multi-Mode Excited Logic Gates on Trapped Ions

Based on the scheme of “hot“ trapped-ion quantum computation proposed by Sφrensen and Mφlmer, we construct a set of multi-mode excited logic gates on trapped ions, which may be operated on arbitrary even number of ions selected randomly from a string of ions trapped in a linear trap. The gate speed may be made faster than that of the corresponding one-mode excited logic gate by adjusting appropriately the detunings of driving lasers with respect to the sidebands of vibrational modes and can be demonstrated in current experimental techniques.     

Optical Digital Logic Operations by Self-pumped Phase Conjugation in Photorefractive Crystal

１ＩｎｔｒｏｄｕｃｔｉｏｎＡｃｏｎｓｉｄｅｒａｂｌｅｒｅｓｅａｒｃｈｅｆｏｒｔｈａｓｂｅｅｎｍａｄｅｄｕｒｉｎｇｔｈｅｐａｓｔｆｅｗｙｅａｒｓｔｏｄｅｖｅｌｏｐｏｐｔｉｃａｌｌｏｇｉｃｏｐｅｒａｔｉｏｎｓｂａｓｅｄｏｎｐｈｏｔｏｒｅｆｒａｃｔｉｖｅｍ...     

Effect of Barrier Width on Bias-Dependent Tunnelling in Ferromagnetic Junctions

We present a finite temperature theory for bias-dependent tunnelling in ferromagnetic tunnelling junctions. The effects of the barrier width d on the tunnelling magnetoresistance (TMR) and its sign change behaviour are discussed with this theory. Numerical results show that both the zero-bias TMR and the critical voltage Vc at which the TMR changes its sign decrease with the increasing barrier width for a considerably thick barrier junction. Furthermore, it is found that a minimum exists in the curve of Vc versus d if a composite junction is under oxidized.     

The Optical Implementation of High Efficiency Packed Redundant Binary Number Addition Based on Boolean Polarization－encoded Logic Algebra

Ｔｈｅ　Ｏｐｔｉｃａｌ　Ｉｍｐｌｅｍｅｎｔａｔｉｏｎ　ｏｆ　Ｈｉｇｈ　Ｅｆｆｉｃｉｅｎｃｙ　Ｐａｃｋｅｄ　Ｒｅｄｕｎｄａｎｔ　Ｂｉｎａｒｙ　Ｎｕｍｂｅｒ　Ａｄｄｉｔｉｏｎ　Ｂａｓｅｄ　ｏｎ　Ｂｏｏｌｅａｎ　Ｐｏｌａｒｉｚａｔｉｏｎ－ｅｎｃｏｄｅｄ　Ｌ...     

Inductive and mesomeric effects on the π orbitals of halobenzenes

Ionization potentials for the π bands of a wide range of fluoro-, chloro-, and bromobenzenes have been measured by the technique of photoelectron spectroscopy. An empirical model incorporating inductive and mesomeric terms is discussed and its validity tested with the observed energies. Satisfactory agreement is obtained with dipole moment data. The theory accurately predicts ionization energies only for molecules having no ortho halogen atoms. Deviations from linearity are adequately explained in terms of an ortho effect which is proportional to the number of halogens situated in ortho positions. An analogous effect has previously been observed in the electronic spectra of substituted benzenes. Application of the model to 1a _2u band shifts in the fluorobenzenes leads to the conclusion that the energy of this band in benzene lies in the region of 11·5 eV.     

Nanoscale Lasers Based on Carbon Peapods

A scheme of nanoscale lasers based on the so-called carbon peapods is examined in detail. Since there is considerable cylindrical empty space in the middle of a single-wall carbon nanotube （SWCNT）, it can serve as a laser resonant cavity that consists of two highly reflecting alignment ＂mirrors＂ separated by a distance. These mirrors refer to the ordered arrays of C6o inside SWCNTs, which have photonic bandgap structures. Meanwhile, ideally single-mode lasers are supposed to be produced in the nanoscale resonant cavity.