Papers by Keyword: Entanglement

Abstract: Nano/Micro-structured CeO₂ and their nanocomposites have been received considerable attention in basic research and commercial applications, such as, new energy fields, photocatalysts, environmental fields, et al. To extend its visible light response and pave the effective conductive channels for charge transfer and separation in nanoscale is still facing great challenges. To explore these key issues of materials chemistry and physics, CeO₂ nanorods were prepared with aid of soft templates by wet chemical approach. Graphene nanoribbons were obtained with unzipping method of carbon nanotube (CNTs). Entanglement of CeO₂ nanorods and graphene nanoribbons oxides was realized based on the supermolecular interactions between surface active groups of CeO₂ nanorods and graphene nanoribbons oxides and excellent flexibility of graphene nanoribbons. A series of characterizations were examined by SEM (scanning electron microscopy), TEM (transmission electron microscopy), XRD (X-ray diffraction), the Fourier-Transform Infrared (FTIR) spectra, ultraviolet-visible spectroscopy (UV-Vis) and so on. Photocatalytic efficiency was examined by selecting typical organic pollutants. The results indicated that the entanglement of a small amount of graphene nanoribbons on the surface of CeO₂ nanorods not only expanded the light response of nanocomposite to visible light, but also enhanced the adsorption properties to organic pollutants. Because of excellent charge transfer properties and high mobility of graphene nanoribbons, the nanocomposites of CeO₂/graphene nanoribbons are favor for electron-holes pairs generated by visible light, separation, and transfer, which would be important potential applications in photocatalysts, artificial photosynthesis system, nano/micro-devices, et al.

Abstract: The effect of arbitrary orientation in the magnetic field on the entanglement and dense coding of a two-qubit XX model is investigated. The concurrence and optimal dense coding capacity are calculated for different orientations of the magnetic field. It is found that the entanglement can be maximized by rotating the magnetic field to an optimal direction at given temperature. Furthermore, there exists critical concurrence C_c, beyond which the thermal state is unfeasible for optimal dense coding.

Abstract: We investigate the entanglement dynamics in a quantum system consisting of three two-level atoms interacting with three spatially separated cavities with the influence of the Stark shift, and we can find that the entanglement sudden death (ESD) and birth (ESB) will be improved by adjusting the Stark parameters. When we choose the appropriate Stark parameters, the phenomena of ESD and ESB will be appeared, but, which will appear earlier than the other depends on the Stark-shift values.

Abstract: We propose a scheme for the generation of three atom W states via the microtoroidal cavity-atom coupling system. This scheme can also be generalized to multi-atom W states. In this paper, three-atom resonant interact simultaneously with two counterpropagating cavity modes which can be produced by embedding Bragg grating in the microtoroidal. A single resonant interaction is required, thus this scheme is simple. Moreover, the required time to complete the whole process almost unchanges with increasing the number of atoms

Abstract: Photosynthesis is a wonderful phenomenon which is present in green plant. In recent years, it has been discovered that there is entanglement in the biological pigment protein complexes, and that may be the reason of high transport efficiency. And coherence also plays an important role during the process of this efficiency energy transport. However, some scientists consider that it is not at all clear entanglement exists in the FMO complex, or unlike coherence, its role for the transport efficiency seems to be irrelevant. This paper mainly introduces what progress have scientists made during the past few years.

Abstract: We proposed a scheme for the generation of multi–atom W states with two-photon Jaynes-Cummings Model in ultrahigh-Q toroidal microcavities. We consider that the two modes, clockwise (CW) and counterclockwise (CCW) modes inside the microtoroidal resonator, can be produced by embedding Bragg grating in the microtoroidal.

Abstract: In present work a new theoretical approach based on the modified three-element Eyring-Halsey mechanical model was used for the derivation of an equation, which describes the thermally-induced recovery of preloaded covalently crosslinked polymer. This approach takes into account the influence of crystallizable polymer network as well as of entangled slipped molecular chains. Modeling of the temperature dependences of shape-memory (SM) recovery strain and SM recovery rate detected at constant heating rate has been performed for three types of polyethylene with sufficiently different crystallinity and crosslink density at programming strain of 100%. The results of modeling agree well with the experimental data. The values of material parameters determined by fitting correspond satisfactorily to the estimations existing in literature. It is shown that the contribution of the entangled slipped molecules to the total stored SM strain increases with increasing degree of branching and crosslink density. The physical sense of main fitting parameters and their dependences on the material constants such as crystallinity are discussed.

Abstract: We report new experimental and theoretical study of mechanical property of aligned and nonaligned (entangled) single walled carbon nanotubes (SWCNTs), and their effect on nanostructures. Experimentally, the contact mode atomic force microscopy cantilever tip is used to measure the Young’s modulus of aligned and nonaligned SWCNTs. The measured Young's modulus of aligned SWCNT bundles ranged between 1100 GPa (1.1 TPa) and 1300 GPa (1.3 TPa) with a relative uncertainty of 5 % whereas that of the entangled SWCNT bundles ranged between 500 GPa and 700 GPa. Young’s modulus increase with aligned SWCNT bundles and then increase their performance in nanostructure comparing with entangled SWCNT bundles. We put emphasis on the combination of physical modeling and reliability based design optimization of nanomaterials. After investigation, we could make suggestions such as how to improve the reliability of nanodevices and nanosystems, and how to reduce cost and economic rates.

Abstract: Quantum information theory is employed to analyze the growing behavior of nanostructured molecules through marginal H-type von Neumann informational entropies. This is achieved by performing ab initio electronic structure calculations at the Hartree-Fock level of theory to characterize the initial steps towards growing Polyamidoamine (PAMAM) dendrimers, starting from conformational structures of polymeric precursors up to generations G0 (with 84 atoms), G1 (228 atoms), G2 (516 atoms), and G3 (1092 atoms). Several physical descriptors like radius of gyration, asphericity factor, moments of inertia and dipole moments, along with chemical reactivity indexes such as total energies, hardness and electrophilicity are employed to provide evidence for the validity of dense-core model of dendrimers.

Abstract: Investigation of the properties of peptide plane in protein chain from both classical and quantum approach is presented. We calculated interatomic force constants for peptide plane and hydrogen bonds between peptide planes in protein chain. On the basis of force constants, displacements of each atom in peptide plane, and time of action we found that the value of the peptide plane action is close to the Planck constant. This indicates that peptide plane from the energy viewpoint possesses synergetic classical/quantum properties. Consideration of peptide planes in protein chain from information viewpoint also shows that protein chain possesses classical and quantum properties. So, it appears that protein chain behaves as a triple dual system: (1) structural - amino acids and peptide planes, (2) energy - classical and quantum state, and (3) information - classical and quantum coding. Based on experimental facts of protein chain, we proposed from the structure-energy-information viewpoint its synergetic code system.