作者机构：
[Zhang, Deng-Yu; Wang, Xin-Wen; Tang, Shi-Qing; Xie, Li-Jun] Hengyang Normal Univ, Dept Phys & Elect Informat, Hengyang 421008, Peoples R China.;[Yang, Guo-Jian] Beijing Normal Univ, Dept Phys, Beijing 100875, Peoples R China.
通讯机构：
[Wang, Xin-Wen] H;Hengyang Normal Univ, Dept Phys & Elect Informat, Hengyang 421008, Peoples R China.
摘要：
Remote information concentration (RIC) in d-level systems (qudits) is studied. It is shown that the quantum information initially distributed in three spatially separated qudits can be remotely and deterministically concentrated to a single qudit via an entangled channel without performing any global operations. The entangled channel can be different types of genuine multipartite pure entangled states which are inequivalent under local operations and classical communication. The entangled channel can also be a mixed entangled state, even a bound entangled state which has a similar form to the Smolin state, but has different features from the Smolin state. A common feature of all these pure and mixed entangled states is found; i.e., they have d2 common commuting stabilizers. The differences of qudit-RIC and qubit-RIC ( d=2) are also analyzed.
通讯机构：
[Wang, Xin-Wen] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
摘要：
We propose a scheme for multiparty hierarchical quantum-information splitting (QIS) with a multipartite entangled state, where a boss distributes a secret quantum state to two grades of agents asymmetrically. The agents who belong to different grades have different authorities for recovering the boss's secret. Except for the boss's Bell-state measurement, no nonlocal operation is involved. The presented scheme is also shown to be secure against eavesdropping. Such a hierarchical QIS is expected to find useful applications in the field of modern multipartite quantum cryptography.
通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
关键词：
Thermodynamic properties;Quasiharmonic approximation;Lattice dynamics;Density functional theory
摘要：
The finite-temperature density functional theory and the quasiharmonic approximation are adopted to investigate thermodynamics properties of hexagonal osmium. By varying lattice volume, the anharmonic effect is part considered in present work. Phonon frequencies calculations are performed from density functional perturbation theory (DFPT). By fitting the total free energy (including both electronic and vibrational parts) to equation of states at different temperatures, some classical thermodynamic quantities and their pressure and temperature dependences are investigated systematically. The results are in good agreement with the available experimental and theoretical data.Research Highlights► The finite-temperature DFT and QHA were adopted. ► Thermodynamic properties were investigated systematically. ► CV reaches a constant (∼3 R) with T approaching to the ΘD. ► CP shows an approximate linear behavior beyond the experimental ΘD. ► The temperature dependence on γ is small.
摘要：
The entanglement dynamics of three-qubit states coupled to a general XY spin-chain with a three-site interaction environment is investigated. By using negativity as entanglement measure, we find that the entanglement evolution depends on not only the system-environment couplings but also the strength of three-site interaction. In the strong-coupling region, the three-site interaction can remarkably enhance the decay of the entanglement of three-qubit states. However, in the weak-coupling region, the process of disentanglement depends on the strength of the three-site interaction.
期刊：
JOURNAL OF PHYSICS-CONDENSED MATTER,2010年22(20):205501 ISSN：0953-8984
通讯作者：
Deng, Xiaohui
作者机构：
[Wang, Wenwei; Deng, Xiaohui; Zhang, Dengyu] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Lu, Wei] Hong Kong Polytech Univ, Dept Appl Phys, Kowloon, Hong Kong, Peoples R China.;[Fan, Bingbing] City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China.;[Fan, Bingbing] City Univ Hong Kong, COSDAF, Hong Kong, Hong Kong, Peoples R China.;[Fan, Bingbing] Zhengzhou Univ, Sch Mat Sci & Engn, Zhengzhou, Henan, Peoples R China.
通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
摘要：
The first-principles spin polarization method is used to investigate the magnetic properties of graphite boron nitride (g-BN) sheet induced by Fe doping. We find that a nitrogen or boron atom substituted by Fe can induce a magnetic moment. From standard Mulliken population analysis, we also find that the magnetic moment is mainly dominated by Fe 3d states. Using Heisenberg exchange coupling theory, we study the exchange coupling mechanisms by constructing two-Fe centers in g-BN. The results show the presence of relatively strong exchange coupling for two-Fe substituted two-B atoms and the coupling is ferromagnetic. For the case of two-Fe substituted two-N atoms, the coupling is antiferromagnetic and the exchange coupling is very weak. The paper enriches recent molecular magnetic investigations.
期刊：
International Journal of Quantum Information,2010年8(8):1301-1314 ISSN：0219-7499
通讯作者：
Wang, Xin-Wen
作者机构：
[Zhang, Deng-Yu; Gao, Feng; Wang, Xin-Wen; Tang, Shi-Qing] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Wang, Xin-Wen] Beijing Normal Univ, Dept Phys, Beijing 100875, Peoples R China.
通讯机构：
[Wang, Xin-Wen] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
关键词：
Quantum secret sharing;GHZ states;security
摘要：
We study the security of multiparty quantum secret sharing (QSS) with multiqubit Greenberger-Horne-Zeilinger states. We give a detailed proof that the original scheme of Xiao et al. [Phys. Rev. A 69 (2004) 052307] is insecure against the interior attack (i.e. the participants' attack) which is the most serious threat for QSS protocols. Thereafter, an improvement of this QSS protocol is proposed.
