title: Quantum random walks on congested lattices and the effect of dephasing.
abstract: We consider quantum random walks on congested lattices and contrast them to classical random walks. Congestion is modelled on lattices that contain static defects which reverse the walker's direction. We implement a dephasing process after each step which allows us to smoothly interpolate between classical and quantum random walks as well as study the effect of dephasing on the quantum walk. Our key results show that a quantum walker escapes a finite boundary dramatically faster than a classical walker and that this advantage remains in the presence of heavily congested lattices.
authors.affiliation: Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney NSW 2113, Australia.
authors.forename: Keith R
authors.initials: KR
authors.lastname: Motes
authors.affiliation: Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney NSW 2113, Australia.
authors.forename: Alexei
authors.initials: A
authors.lastname: Gilchrist
authors.affiliation: Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney NSW 2113, Australia.|Centre for Quantum Computation and Intelligent Systems (QCIS), Faculty of Engineering &Information Technology, University of Technology Sydney, NSW 2007, Australia.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Rohde
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