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Complementarity and quantum walks

Viv Kendon·Barry C. Sanders
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Abstract

We show that quantum walks interpolate between a coherent `wave walk' and a random walk depending on how strongly the walker's coin state is measured; i.e., the quantum walk exhibits the quintessentially quantum property of complementarity, which is manifested as a trade-off between knowledge of which path the walker takes vs the sharpness of the interference pattern. A physical implementation of a quantum walk (the quantum quincunx) should thus have an identifiable walker and the capacity to demonstrate the interpolation between wave walk and random walk depending on the strength of measurement.

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Viv Kendon, Barry C. Sanders. 2004-11-09. Complementarity and quantum walks. https://doi.org/10.1103/physreva.71.022307

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