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991.
Ya-fei Yu Jian Feng Xiao-qing Zhou Ming-sheng Zhan 《International Journal of Theoretical Physics》2004,43(1):21-26
We construct a quantum machine which, by using an asymmetric cloner, disentangles an entangled state and nearly retains it. The attainable maximum value of the scaling parameter for disentangling is identical to that obtained in previous works. The fidelity of the output residual entangled state with respect to the input entangled state is state-dependent. The result shows that it is possible to deal with disentanglement and broadcasting entanglement in a single unitary evolution. 相似文献
992.
推广了著名的Boutroux—Cartan定理。设aμ(μ=1,2,…,n)为复平面上任意的n个点,H为任意的一个正数,则在平面上同时使得n∏μ=1 |z-aμ|≤(H/e)^n和n∑μ=1 1/|z-aμ|≥nlog(en)/H成立的点z可被含于总数不超过n,半径总和不超过2H的一组圈内。 相似文献
993.
994.
995.
In this paper, we propose a protocol which can realize quantum cloning of an unknown tripartite entangled state and its orthogonal
complement state with assistance from a state preparer. The first stage of the protocol requires usual teleportation via three
entangled particle pairs as quantum channel. In the second stage of the protocol, the perfect copies and complement copies
of an unknown state can be produced with the assistance (through a tripartite projective measurement) of the state preparer.
We also present a scheme for the teleportation by using non-maximally entangled quantum channel. It is shown that the clones
and complement clones of the unknown state can be obtained with certain probability in the latter scheme. 相似文献
996.
Jian-Ping Zhou Hong-Cai He Yi Zhang Chao-Yong Deng Zhan Shi Ce-Wen Nan 《Applied Physics A: Materials Science & Processing》2007,89(2):553-558
CoFe2O4 (CFO) thin film with highly (111)-preferential orientation was first deposited on the silicon substrate by a pulsed-laser
deposition, and then Pb(Zr0.52Ti0.48)O3 (PZT) layers were deposited with different oxygen pressures to form the bilayer CFO/PZT nanocomposite thin films. X-ray diffraction
showed that the PZT preferential orientation was strongly dependant on the oxygen pressure. The smooth film surface was obtained
after depositing the CFO and PZT layers. The bilayer thin films exhibit good ferromagnetic and ferroelectric properties, and
a low leakage current density of 0.004 μA/cm2 at 50 kV/cm. The leakage current density curves show loops for the electric polarized field when the electric field reverses.
PACS 77.84.Lf; 75.80+q; 81.05.Zx; 81.15.Fg 相似文献
997.
This paper has observed linewidth narrowing of dark states in rubidium cell by using the Hanle configuration. The reduction of the coherent resonance width under the transition of ^87Rb Fg = 1 → Fe = 0 is observed and the qualitative explanation about its mechanism is presented. Multiple subnatural width dips are obtained with a linearly polarized laser beam for the transitions of ^87Rb Fg = 1→Fe = 0, 1, 2. The feature of negative and positive slope, namely dispersionlike feature, is observed in the transmitted light. 相似文献
998.
This paper presents a scheme for probabilistic remote preparation of a three-particle entangled Greenberger-Horne-Zeilinger (GHZ) state via three-particle orthonormal basis projective measurement, and then directly generalize the scheme to multi-particle case. It is shown that by using N pairs of bipartite non-maximally entangled states as the quantum channel and N-particle orthonormal basis projective measurement, the multi-particle remote preparation can be successfully realized with a certain probability. 相似文献
999.
The growth of Mn5Ge3 ultrathin films with different thicknesses, prepared by solid phase epitaxy, is studied. The results of scanning tunnelling microscopy and low energy electron diffraction studies show that the film can be formed and it is terminated with a (√3 × √3) R30° surface reconstruction when the thickness of Mn exceeds 3 monolayers. The magnetic properties show that the Curie temperature is about 300 K and the T^2-dependent behaviour is observed to remain up to 220 K. 相似文献
1000.
Different chaos synchronization based encryption schemes are reviewed and compared from the practical point of view. As an efficient cryptanalysis tool for chaos encryption, a proposal based on the error function attack is presented systematically and used to evaluate system security. We define a quantitative measure (quality factor) of the effective applicability of a chaos encryption scheme, which takes into account the security, the encryption speed, and the robustness against channel noise. A comparison is made of several encryption schemes and it is found that a scheme based on one-way coupled chaotic map lattices performs outstandingly well, as judged from quality factor. 相似文献