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From Coupled Pendulums to Quantum Search

Lov K. Grover·Anirvan Sengupta
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Abstract

Quantum search is a quantum mechanical technique for searching N possibilities in only sqrt(N) steps. This paper gives a fresh perspective on the algorithm in terms of a resonance phenomenon which is implemented through classical coupled oscillators. Consider N oscillators, one of which is of a different resonant frequency. We could identify which one this is by measuring the oscillation frequency of each oscillator, a procedure that would take about N cycles. We show how, by coupling the oscillators together in a very simple way, it is possible to identify the different one in only sqrt(N) cycles. An extension of this technique to the quantum case leads to the quantum search algorithm.

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Lov K. Grover, Anirvan Sengupta. 2001-09-26. From Coupled Pendulums to Quantum Search. https://arxiv.org/abs/quant-ph/0109123

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