Environment-Induced Entanglement for a Tripartite System in Non-Markovian Dissipation

We show that entanglement between three two-level atoms can be generated if the three atoms interact with a common structured reservoir, but do not interact directly with each other. Comparing with the results in Markovian case, we find that much higher values of bipartite and tripartite entanglement can be obtained for an initially factorized state of the tripartite system. The maximal value of entanglement depends on the detuning and the strength of relative coupling between the atoms and the reservoir.     

The Quantum Search Algorithms for All Solutions

Two quantum search algorithms are proposed for known and unknown number of solutions. The first algorithm begins with an arbitrary rotation phase Grover search algorithm by recursive equations, then a sub-algorithm (G _α algorithm) and the corresponding quantum circuits are designed, the probability of success and expected number of iterations of the sub-algorithm to find a solution are analyzed. Based on these results, we design the whole algorithm and estimate the expected number of iterations to search all solutions. The design of the second algorithm follows the same steps. We firstly study a quantum counting algorithm, then design a sub-algorithm (QCG algorithm), and analyze the probability of success and the expected number of iterations to find a solution. Finally the whole algorithm for all solutions is designed and analyzed. The analysis results show that these two algorithms find all solutions in the expected times of $O(t\sqrt{N})$ (t is a number of solutions and N is a total of states).     

Theoretical investigation of the spin-Hamiltonian parameters and optical spectra for the doped Cu2+ in ZnCdO nanopowder

The spin-Hamiltonian (SH) parameters (g factors g_||, g_⊥ and hyperfine structure constants A_||, A_⊥) and d–d transitions for ZnCdO:Cu²⁺ are calculated based on the perturbation formulas for a 3d⁹ ion in tetragonally elongated octahedra. Good agreement between the calculated results (four SH parameters and three optical absorption bands) and the experimental results can be obtained. Since the SH parameters are sensitive to the local structure of a paramagnetic impurity center, the tetragonal distortion (characterized by the relative elongation ratio ρ ≈ 3.5% along the C₄ axis) of the impurity center due to the Jahn–Teller effect is also acquired from the calculations. The negative and positive signs of hyperfine structure constants A_|| and A_⊥ for ZnCdO:Cu²⁺, respectively, are also suggested in the discussions.     

Efficient Fluorescent Recognition of Carboxylates in Aqueous Media Using Facilely Electrosynthesized Poly(9-Aminofluorene)

A variety of carboxylates were recognized using poly(9-aminofluorene) (P9AF) in the HEPES buffer (pH 7.4), and a proposed possible mechanism was proposed as following. The intermolecular hydrogen bonding interactions resulted in electron transfer between P9AF and carboxylates. P9AF was facilely electrosynthesized in boron trifluoride diethyl etherate and could be used as an efficient fluorescent sensing material for the detection of AcO^?. On binding to AcO^?, fluorescence quenching of P9AF was demonstrated by a maximum 80 % reduction in the fluorescence intensity, while no obvious fluorescence change could be observed in the presence of some other common anions. Some different carboxylates could be recognized at different levels by P9AF. Substituent groups in carboxylates could affect the intermolecular interaction between carboxylates and P9AF. These could be explained by a possible mechanism that hydrogen bonding was the main way of intermolecular interactions between P9AF and carboxylates, which was further confirmed by absorption spectra monitoring and density functional calculations. The significant advantage of this strategy is that it does not require a prequenching procedure and the polymer can be used directly for analyte detection.     

Control of electronic state in organic conductors by systematic band filling

Organic superconductors have been usually obtained by the bandwidth control of antiferromagnetic insulator. In order to find another parameter to control the electronic state, the band filling control has been applied to obtain the carrier-controlled organic conductors. As a result, the systematic band filling control for four kinds of organic conductors has been succeeded. The obtained crystals were (a) 2:1 salts, λ-ET₂(GaCl₄¹⁻)_1−x(CoCl₄²⁻)_x [ET=bis(ethylenedithio)tetrathiafulvalene], doping to the antiferromagnetic insulator, (b) 2:1 salts, δ′-ET₂(GaCl₄)_1−x(CoCl₄)_x, doping to the non-magnetic insulator, (c) 3:1 salts, α-ET₃(CoCl₄)_1−x(GaCl₄)_x(TCE), doping to the charge ordered salt, and (d) 3:2 salts, β′-ET₃(CoCl₄)_2−x(GaCl₄)_x, doping to the half-filled band insulator. For both 2:1 salts, (a) and (b), the semiconducting behaviors have transferred to relatively conductive semiconducting ones by doping. The largest change of transport property is observed for (d) β′-phase from semiconducting behavior of parent material to metallic ones [β′-ET₃(CoCl₄)_2−x(GaCl₄)_x (x=0.88, 0.66)] down to 140 and 100 K, respectively.These systematic band filling control suggests that the doping to the 1/2-filled band insulator is most effective.     

Optical properties of cubic and tetragonal KTa0.5Nb0.5O3 by density functional theory

Using density functional methods, optical properties of KTa_0.5Nb_0.5O₃ (KTN) are investigated. The imaginary part of dielectric function ε₂(ω), the optical absorption coefficient I(ω) and the reflectivity R(ω) of KTN in the cubic (paraelectric) and tetragonal (ferroelectric) phases are calculated. The origin of the different behavior of the optical spectra between the two phases is discussed.     

An extension of the mean free path approach to X-ray absorption spectroscopy

In the partial electron yield (PEY) acquisition mode commonly used in X-ray absorption spectroscopy (XAS) both elastically and inelastically scattered electrons are acquired, the latter contribution dominating the detector signal. Hence, the majority of the inelastic scattering events will not result in signal attenuation as happens in the case of X-ray photoelectron spectroscopy (XPS). To determine the respective changes in the effective mean free paths (MFP) we have performed XPS and near edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements for a series of self-assembled monolayers of alkanethiols on gold substrates. The length of the alkyl chain and, therefore, the film thickness was varied. In agreement with expectations, the obtained MFPs for the Au 4f photoelectrons and C_KLL Auger electrons in the PEY acquisition mode (with the respective inelastic contributions) exceed the corresponding values for the Au 4f and C_KLL electrons of the same kinetic energies in the constant final state acquisition mode. Furthermore, the effective PEY-MFP for the C_KLL Auger electrons increased with decreasing retarding voltage of the PEY detector, which correlates with the enhanced contribution of the inelastically scattered electrons in the acquired signal. The results obtained are of importance for the analysis of XAS spectra of thin organic films and polymers.     

Flexible metal–insulator–metal (MIM) devices for plastic film AM-LCD

We developed new flexible metal–insulator–metal (MIM) devices subject to plastic film substrate. The structure of the MIM device is that a Ta₂O₅ insulator is covered with two flexible Al electrodes on both sides. The flexible structure of the MIM device was successfully fabricated applying our own etch-free process.     

Layered xLiMO2·(1−x)Li2M′O3 electrodes for lithium batteries: a study of 0.95LiMn0.5Ni0.5O2·0.05Li2TiO3

The electrochemical properties of 0.95LiMn_0.5Ni_0.5O₂·0.05Li₂TiO₃ have been investigated as part of a study of xLiMO₂·(1−x)Li₂M^′O₃ electrode systems for lithium batteries in which M=Co, Ni, Mn and M^′=Ti, Zr, Mn. The data indicate that the electrochemically inactive Li₂TiO₃ component contributes to the stabilization of LiMn_0.5Ni_0.5O₂ electrodes, which improves the coulombic efficiency of Li/xLiMn_0.5Ni_0.5O₂·(1−x)Li₂TiO₃ cells for x<1. The 0.95LiMn_0.5Ni_0.5O₂·0.05Li₂TiO₃ electrodes provide a rechargeable capacity of approximately 175 mAh/g at 50 °C when cycled between 4.6 and 2.5 V; there is no indication of spinel formation during electrochemical cycling.