中国物理B ›› 2015, Vol. 24 ›› Issue (8): 80307-080307.doi: 10.1088/1674-1056/24/8/080307

• GENERAL • 上一篇    下一篇

Decoherence in optimized quantum random-walk search algorithm

张宇超a b, 鲍皖苏a b, 汪翔a b, 付向群a b   

  1. a Zhengzhou Information Science and Technology Institute, Zhengzhou 450004, China;
    b Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2015-01-06 修回日期:2015-03-11 出版日期:2015-08-05 发布日期:2015-08-05
  • 基金资助:
    Project supported by the National Basic Research Program of China (Grant No. 2013CB338002).

Decoherence in optimized quantum random-walk search algorithm

Zhang Yu-Chao (张宇超)a b, Bao Wan-Su (鲍皖苏)a b, Wang Xiang (汪翔)a b, Fu Xiang-Qun (付向群)a b   

  1. a Zhengzhou Information Science and Technology Institute, Zhengzhou 450004, China;
    b Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
  • Received:2015-01-06 Revised:2015-03-11 Online:2015-08-05 Published:2015-08-05
  • Contact: Bao Wan-Su E-mail:2010thzz@sina.com
  • Supported by:
    Project supported by the National Basic Research Program of China (Grant No. 2013CB338002).

摘要: This paper investigates the effects of decoherence generated by broken-link-type noise in the hypercube on an optimized quantum random-walk search algorithm. When the hypercube occurs with random broken links, the optimized quantum random-walk search algorithm with decoherence is depicted through defining the shift operator which includes the possibility of broken links. For a given database size, we obtain the maximum success rate of the algorithm and the required number of iterations through numerical simulations and analysis when the algorithm is in the presence of decoherence. Then the computational complexity of the algorithm with decoherence is obtained. The results show that the ultimate effect of broken-link-type decoherence on the optimized quantum random-walk search algorithm is negative.

关键词: quantum search algorithm, quantum random walk, decoherence

Abstract: This paper investigates the effects of decoherence generated by broken-link-type noise in the hypercube on an optimized quantum random-walk search algorithm. When the hypercube occurs with random broken links, the optimized quantum random-walk search algorithm with decoherence is depicted through defining the shift operator which includes the possibility of broken links. For a given database size, we obtain the maximum success rate of the algorithm and the required number of iterations through numerical simulations and analysis when the algorithm is in the presence of decoherence. Then the computational complexity of the algorithm with decoherence is obtained. The results show that the ultimate effect of broken-link-type decoherence on the optimized quantum random-walk search algorithm is negative.

Key words: quantum search algorithm, quantum random walk, decoherence

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

  • 03.67.Lx
03.67.Ac (Quantum algorithms, protocols, and simulations)