@article{Brun2003QuantumTC,
title={Quantum to classical transition for random walks.},
author={T. Brun and H. Carteret and A. Ambainis},
journal={Physical review letters},
year={2003},
volume={91 13},
pages={
130602
}
}

We look at two possible routes to classical behavior for the discrete quantum random walk on the integers: decoherence in the quantum "coin" which drives the walk, or the use of higher-dimensional (or multiple) coins to dilute the effects of interference. We use the position variance as an indicator of classical behavior and find analytical expressions for this in the long-time limit; we see that the multicoin walk retains the "quantum" quadratic growth of the variance except in the limit of a… Expand