Bao-Kui Zhao

Publications (7)0 Total impact

• Source

  Available from: ArXiv

  Article: Residual effect on the robustness of multiqubit entanglement

  Bao-Kui Zhao, Fu-Guo Deng
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  ABSTRACT: We investigate the relation between the entanglement and the robustness of a multipartite system to a depolarization noise. We find that the robustness of a two-qubit system in an arbitrary pure state depends completely on its entanglement. However, this is not always true in a three-qubit system. There is a residual effect on the robustness of a three-qubit system in an arbitrary superposition of Greenberger-Horne-Zeilinger state and W state. Its entanglement determines the trend of its robustness. However, there is a splitting on its robustness under the same entanglement. Its robustness not only has the same periodicity as its three-tangle but also alters with its three-tangle synchronously. There is also a splitting on the robustness of an $n$-qubit ($n>3$) system although it is more complicated. Comment: 5 pages, 4 figures; A figure is added, compared with the version published in Phys. Rev. A 82, 014301 (2010)
  07/2010;
• Source

  Available from: ArXiv

  Article: Genuine tripartite entanglement in quantum brachistochrone evolution of a three-qubit system

  Bao-Kui Zhao, Fu-Guo Deng, Feng-Shou Zhang, Hong-Yu Zhou
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  ABSTRACT: We explore the connection between quantum brachistochrone (time-optimal) evolution of a three-qubit system and its residual entanglement called three-tangle. The result shows that the entanglement between two qubits is not required for some brachistochrone evolutions of a three-qubit system. However, the evolution between two distinct states cannot be implemented without its three-tangle, except for the trivial cases in which less than three qubits attend evolution. Although both the probability density function of the time-averaged three-tangle and that of the time-averaged squared concurrence between two subsystems become more and more uniform with the decrease in angles of separation between an initial state and a final state, the features of their most probable values exhibit a different trend. Comment: 6 pages, 3 figures
  06/2009;
• Source

  Available from: ArXiv

  Article: Fault tolerant quantum key distribution based on quantum dense coding with collective noise

  Xi-Han Li, Bao-Kui Zhao, Yu-Bo Sheng, Fu-Guo Deng, Hong-Yu Zhou
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  ABSTRACT: We present two robust quantum key distribution protocols against two kinds of collective noise, following some ideas in quantum dense coding. Three-qubit entangled states are used as quantum information carriers, two of which forming the logical qubit which is invariant with a special type of collective noise. The information is encoded on logical qubits with four unitary operations, which can be read out faithfully with Bell-state analysis on two physical qubits and a single-photon measurement on the other physical qubit, not three-photon joint measurements. Two bits of information are exchanged faithfully and securely by transmitting two physical qubits through a noisy channel. When the losses in the noisy channel is low, these protocols can be used to transmit a secret message directly in principle. Comment: 5 page, no figures
  03/2009;
• Source

  Available from: ArXiv

  Article: Multipartite entanglement purification with quantum nondemolition detectors

  Yu-Bo Sheng, Fu-Guo Deng, Bao-Kui Zhao, Tie-Jun Wang, Hong-Yu Zhou
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  ABSTRACT: We present a scheme for multipartite entanglement purification of quantum systems in a Greenberger-Horne-Zeilinger state with quantum nondemolition detectors (QNDs). This scheme does not require the controlled-not gates which cannot be implemented perfectly with linear optical elements at present, but QNDs based on cross-Kerr nonlinearities. It works with two steps, i.e., the bit-flipping error correction and the phase-flipping error correction. These two steps can be iterated perfectly with parity checks and simple single-photon measurements. This scheme does not require the parties to possess sophisticated single photon detectors. These features maybe make this scheme more efficient and feasible than others in practical applications. Comment: 8 pages, 5 figures
  10/2008;
• Source

  Available from: ArXiv

  Article: Stable and deterministic quantum key distribution based on differential phase shift

  Bao-Kui Zhao, Yu-Bo Sheng, Fu-Guo Deng, Feng-Shou Zhang, Hong-Yu Zhou
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  ABSTRACT: We present a stable and deterministic quantum key distribution (QKD) system based on differential phase shift. With three cascaded Mach-Zehnder interferometers with different arm-length differences for creating key, its key creation efficiency can be improved to be 7/8, more than other systems. Any birefringence effects and polarization-dependent losses in the long-distance fiber are automatically compensated with a Faraday mirror. Added an eavesdropping check, this system is more secure than some other phase-coding-based QKD systems. Moreover, the classical information exchanged is reduces largely and the modulation of phase shifts is simplified. All these features make this QKD system more convenient than others in a practical application. Comment: 5 pages, 2 figures
  12/2007;
• Article: Investigation of discrete γ radiation in interactions of 14.9-MeV neutrons with natural silicon by a total γ-radiation measurement technique

  Hong-Yu Zhou, Fu-Guo Deng, Qiang Zhao, Jun Su, Bao-Kui Zhao, Li-Ming Dong, Guo-Ying Fan, Feng-Shou Zhang
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  ABSTRACT: The discrete γ radiation in the interaction of 14.9-MeV neutrons and a natural silicon sample is investigated with a total γ-radiation measurement (TGRM) technique. Fifty prompt γ lines, one delayed γ line, and seven final nuclei are identified. Forty-one possible transitions are designated. Differential production cross sections of 40 γ lines at 40°, 55°, 90°, 125°, and 140° are determined. Using relative differential production cross sections, accurate integral isotopic cross sections of the 28Si(n,p)28Al reaction are determined, and partial integral isotopic cross sections of the 28Si(n,n′)28Si, 28Si(n,α)25Mg, 29Si(n,n′)29Si, and 30Si(n,n′)30Si reaction channels are also estimated. The present results are in good agreement with some recent experimental and evaluated results.
  Phys. Rev. C. 82(4).
• Source

  Available from: ArXiv

  Article: Efficient faithful qubit transmission with frequency degree of freedom

  Xi-Han Li, Bao-Kui Zhao, Yu-Bo Sheng, Fu-Guo Deng, Hong-Yu Zhou
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  ABSTRACT: We propose an efficient faithful polarization-state transmission scheme by utilizing frequency degree of freedom besides polarization and an additional qubit prepared in a fixed polarization. An arbitrary single-photon polarization state is protected against the collective noise probabilistically. With the help of frequency beam splitter and frequency shifter, the success probability of our faithful qubit transmission scheme with frequency degree of freedom can be 1/2 in principle.
  Optics Communications.