Search by Quantum Walks on Two-Dimensional Grid without Amplitude Amplification
Search by Quantum Walks on Two-Dimensional Grid without Amplitude Amplification
复制标题
无振幅放大的二维网格上的量子行走搜索
DOI:
10.1007/978-3-642-35656-8_7
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发表时间:
2011
期刊:
影响因子:
--
通讯作者:
Alexander Rivosh
中科院分区:
文献类型:
--
作者:
A. Ambainis;A. Backurs;N. Nahimovs;Raitis Ozols;Alexander Rivosh
We study search by quantum walk on a finite two dimensional grid. The algorithm of Ambainis, Kempe, Rivosh [AKR05] usessteps and finds a marked location with probabilityO(1 / logN) for grid of size. This probability is small, thus [AKR05] needs amplitude amplification to get Θ(1) probability. The amplitude amplification adds an additionalfactor to the number of steps, making it.In this paper, we show that despite a small probability to find a marked location, the probability to be withinneighbourhood (at $O(\sqrt[4]{N})$ distance) of the marked location is Θ(1). This allows to skip amplitude amplification step and leads tospeed-up.