White Noise in Quantum Random Walk Search Algorithm
MA Lei1,2, DU Jiang-Feng1,3, LI Yun2, LI Hui3, KWEK L. C.1,4,OH C.H.1
1Department of Physics, Faculty of Science, National University of Singapore, 10 Lower Kent Ridge, Singapore 119260
2Department of Physics, East China Normal University, Shanghai 200062
3Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026
4National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 639798
White Noise in Quantum Random Walk Search Algorithm
MA Lei1,2;DU Jiang-Feng1,3;LI Yun2;LI Hui3;KWEK L. C.1,4,OH C.H.1
1Department of Physics, Faculty of Science, National University of Singapore, 10 Lower Kent Ridge, Singapore 119260
2Department of Physics, East China Normal University, Shanghai 200062
3Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026
4National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore 639798
Abstract： The quantum random walk is a possible approach to construct new quantum search algorithms. It has been shown by Shenvi et al. [Phys. Rev. A 67(2003)52307] that a kind of algorithm can perform an oracle search on a database of N items with O(√N) calling to the oracle, yielding a speedup similar to other quantum search algorithms. We study the effect of white or Gaussian noise on this algorithm. The algorithm loses efficiency when noise is added. We also show that noise on the target state plays a more important role than that on other states. Finally we compare the effects of similar types of noise in the quantum random walk search algorithm and Grover's search algorithm.
MA Lei;DU Jiang-Feng;LI Yun;LI Hui;KWEK L. C.;OH C.H.. White Noise in Quantum Random Walk Search Algorithm[J]. 中国物理快报, 2006, 23(4): 779-782.
MA Lei, DU Jiang-Feng, LI Yun, LI Hui, KWEK L. C., OH C.H.. White Noise in Quantum Random Walk Search Algorithm. Chin. Phys. Lett., 2006, 23(4): 779-782.
2006, Vol. 23 
