dorsal/arxiv
View SchemaQuantum random walks with decoherent coins
| Authors | Todd A. Brun, Hilary A. Carteret, Andris Ambainis |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0210180 |
| URL | https://arxiv.org/abs/quant-ph/0210180 |
| DOI | 10.1103/PhysRevA.67.032304 |
| Journal | Phys. Rev. A 67, 032304 (2003). |
Abstract
The quantum random walk has been much studied recently, largely due to its highly nonclassical behavior. In this paper, we study one possible route to classical behavior for the discrete quantum walk on the line: the presence of decoherence in the quantum ``coin'' which drives the walk. We find exact analytical expressions for the time dependence of the first two moments of position, and show that in the long-time limit the variance grows linearly with time, unlike the unitary walk. We compare this to the results of direct numerical simulation, and see how the form of the position distribution changes from the unitary to the usual classical result as we increase the strength of the decoherence.
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"abstract": "The quantum random walk has been much studied recently, largely due to its\nhighly nonclassical behavior. In this paper, we study one possible route to\nclassical behavior for the discrete quantum walk on the line: the presence of\ndecoherence in the quantum ``coin\u0027\u0027 which drives the walk. We find exact\nanalytical expressions for the time dependence of the first two moments of\nposition, and show that in the long-time limit the variance grows linearly with\ntime, unlike the unitary walk. We compare this to the results of direct\nnumerical simulation, and see how the form of the position distribution changes\nfrom the unitary to the usual classical result as we increase the strength of\nthe decoherence.",
"arxiv_id": "quant-ph/0210180",
"authors": [
"Todd A. Brun",
"Hilary A. Carteret",
"Andris Ambainis"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.67.032304",
"journal_ref": "Phys. Rev. A 67, 032304 (2003).",
"title": "Quantum random walks with decoherent coins",
"url": "https://arxiv.org/abs/quant-ph/0210180"
},
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