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Quantum spatial search on graphs subject to dynamical noise




TekijätCattaneo M, Rossi MAC, Paris MGA, Maniscalco S

KustantajaAmerican Physical Society

Julkaisuvuosi2018

JournalPhysical Review A

Tietokannassa oleva lehden nimiPhys. Rev. A

Lehden akronyymiPhys. Rev. A

Artikkelin numero052347

Vuosikerta98

Numero5

DOIhttps://doi.org/10.1103/PhysRevA.98.052347

Verkko-osoitehttps://link.aps.org/doi/10.1103/PhysRevA.98.052347

Rinnakkaistallenteen osoitehttps://arxiv.org/abs/1809.01969v2


Tiivistelmä

We address quantum spatial search on graphs and its implementation by continuous-time quantum walks in the presence of dynamical noise. In particular, we focus on search on the complete graph and on the star graph of order N, also proving that noiseless spatial search shows optimal quantum speedup in the latter, in the computational limit N≫1. The noise is modeled by independent sources of random telegraph noise (RTN), dynamically perturbing the links of the graph. We observe two different behaviors depending on the switching rate of RTN: fast noise only slightly degrades performance, whereas slow noise is more detrimental and, in general, lowers the success probability. In particular, we still find a quadratic speedup for the average running time of the algorithm, while for the star graph with external target node, we observe a transition to classical scaling. We also address how the effects of noise depend on the order of the graphs and discuss the role of the graph topology. Overall, our results suggest that realizations of quantum spatial search are possible with current technology and indicate the star graph as the perfect candidate for the implementation by noisy quantum walks, owing to its simple topology and nearly optimal performance for just a few nodes also.



Last updated on 2024-26-11 at 17:06