中国物理B ›› 2009, Vol. 18 ›› Issue (1): 23-29.doi: 10.1088/1674-1056/18/1/004

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Implementation of quantum search scheme by adiabatic passage in a cavity--laser--atom system

刘文武, 李洪才, 杨榕灿   

  1. School of Physics and Optoelectronics Technology, Fujian Normal University, Fuzhou 350007, China
  • 收稿日期:2008-02-16 修回日期:2008-05-21 出版日期:2009-01-20 发布日期:2009-01-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574022 and 10575022), and the Funds of Educational Committee of Fujian Province, China (Grant No JB07043).

Implementation of quantum search scheme by adiabatic passage in a cavity--laser--atom system

Liu Wen-Wu(刘文武), Li Hong-Cai(李洪才), and Yang Rong-Can(杨榕灿)   

  1. School of Physics and Optoelectronics Technology, Fujian Normal University, Fuzhou 350007, China
  • Received:2008-02-16 Revised:2008-05-21 Online:2009-01-20 Published:2009-01-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574022 and 10575022), and the Funds of Educational Committee of Fujian Province, China (Grant No JB07043).

摘要: This paper proposes a scheme for implementing the adiabatic quantum search algorithm of different marked items in an unsorted list of N items with atoms in a cavity driven by lasers. N identical three-level atoms are trapped in a single-mode cavity. Each atom is driven by a set of three pulsed laser fields. In each atom, the same level represents a database entry. Two of the atoms are marked differently. The marked atom has an energy gap between its two ground states. The two different marked states can be sought out respectively starting from an initial entangled state by controlling the ratio of three pulse amplitudes. Moreover, the mechanism, based on adiabatic passage, constitutes a decoherence-free method in the sense that spontaneous emission and cavity damping are avoided since the dynamics follows the dark state. Furthermore, this paper extends the algorithm with m (m>2) atoms marked in an ideal situation. Any different marked state can be sought out.

关键词: adiabatic quantum search algorithm, cavity--laser--atom system, marked state

Abstract: This paper proposes a scheme for implementing the adiabatic quantum search algorithm of different marked items in an unsorted list of N items with atoms in a cavity driven by lasers. N identical three-level atoms are trapped in a single-mode cavity. Each atom is driven by a set of three pulsed laser fields. In each atom, the same level represents a database entry. Two of the atoms are marked differently. The marked atom has an energy gap between its two ground states. The two different marked states can be sought out respectively starting from an initial entangled state by controlling the ratio of three pulse amplitudes. Moreover, the mechanism, based on adiabatic passage, constitutes a decoherence-free method in the sense that spontaneous emission and cavity damping are avoided since the dynamics follows the dark state. Furthermore, this paper extends the algorithm with m (m>2) atoms marked in an ideal situation. Any different marked state can be sought out.

Key words: adiabatic quantum search algorithm, cavity--laser--atom system, marked state

中图分类号:  (Quantum computation architectures and implementations)

  • 03.67.Lx
03.65.Ud (Entanglement and quantum nonlocality) 42.50.Dv (Quantum state engineering and measurements)