TY - JOUR

T1 - Engineering the success of quantum walk search using weighted graphs

AU - Wong, Thomas G.

AU - Philipp, Pascal

N1 - Funding Information:
T.W. was supported by the European Union Seventh Framework Programme (FP7/2007-2013) under the QALGO (Grant Agreement No. 600700) project, and the ERC Advanced Grant MQC. P.P. was supported by CNPq CSF/BJT Grants No.? 400216/2014-0 and No.? 150726/2015-5.
Publisher Copyright:
© 2016 American Physical Society.

PY - 2016/8/4

Y1 - 2016/8/4

N2 - Continuous-time quantum walks are natural tools for spatial search, where one searches for a marked vertex in a graph. Sometimes the structure of the graph causes the walker to get trapped, such that the probability of finding the marked vertex is limited. We give an example with two linked cliques, proving that the captive probability can be liberated by increasing the weights of the links. This allows the search to succeed with probability 1 without increasing the energy scaling of the algorithm. Further increasing the weights, however, slows the runtime, so the optimal search requires weights that are neither too weak nor too strong.

AB - Continuous-time quantum walks are natural tools for spatial search, where one searches for a marked vertex in a graph. Sometimes the structure of the graph causes the walker to get trapped, such that the probability of finding the marked vertex is limited. We give an example with two linked cliques, proving that the captive probability can be liberated by increasing the weights of the links. This allows the search to succeed with probability 1 without increasing the energy scaling of the algorithm. Further increasing the weights, however, slows the runtime, so the optimal search requires weights that are neither too weak nor too strong.

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U2 - 10.1103/PhysRevA.94.022304

DO - 10.1103/PhysRevA.94.022304

M3 - Article

AN - SCOPUS:84983469990

VL - 94

JO - Physical Review A - Atomic, Molecular, and Optical Physics

JF - Physical Review A - Atomic, Molecular, and Optical Physics

SN - 1050-2947

IS - 2

M1 - 022304

ER -