Quantum walks driven by many coins
- Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540 (United States)
- Department of Combinatorics and Optimization, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)
Quantum random walks have been much studied recently, largely due to their highly nonclassical behavior. In this paper, we study one possible route to classical behavior for the discrete quantum random walk on the line: the use of multiple quantum 'coins' (or more generally, coins of higher dimension) in order to diminish the effects of interference between paths. We find solutions to this system in terms of the single-coin random walk, and compare the asymptotic limit of these solutions to numerical simulations. We find exact analytical expressions for the time dependence of the first two moments, and show that in the long-time limit the ''quantum-mechanical'' behavior of the one-coin walk persists, even if each coin is flipped only twice. We further show that this is generic for a very broad class of possible walks, and that this behavior disappears only in the limit of a new coin for every step of the walk.
- OSTI ID:
- 20636366
- Journal Information:
- Physical Review. A, Vol. 67, Issue 5; Other Information: DOI: 10.1103/PhysRevA.67.052317; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
Similar Records
Asymptotic evolution of quantum walks on the N-cycle subject to decoherence on both the coin and position degrees of freedom
A simple coin for a 2d entangled walk