Discrete Single-Photon Quantum Walks with Tunable Decoherence

Broome, Matthew A.; Fedrizzi, Alessandro; Lanyon, B. P.; Kassal, Ivan; Aspuru‐Guzik, Alán; White, A. G.

doi:10.1103/physrevlett.104.153602

Cited by 410 publications

(440 citation statements)

References 33 publications

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“…Such configurations have been systematically employed to investigate a number of issues ranging from discrete quantum walks [44][45][46][47] to Bloch oscillations and fractal patterns [43,48]. While spatial realizations of such mesh lattices have also been reported [47,49], time-multiplexed fiber loop schemes have so far demonstrated a high degree of flexibility [43,45].…”

Section: Optical Mesh Lattices In the Time Domainmentioning

confidence: 99%

Optical mesh lattices withPTsymmetry

Miri

Regensburger

Peschel³

et al. 2012

Phys. Rev. A

109

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We investigate a new class of optical mesh periodic structures that are discretized in both the transverse and longitudinal directions. These networks are composed of waveguide arrays that are discretely coupled while phase elements are also inserted to discretely control their effective potentials and can be realized both in the temporal and the spatial domain. Their band structure and impulse response is studied in both the passive and parity-time (PT ) symmetric regime. The possibility of band merging and the emergence of exceptional points along with the associated optical dynamics are considered in detail both above and below the PT -symmetry breaking point. Finally unidirectional invisibility in PT -synthetic mesh lattices is also examined along with possible superluminal light transport dynamics.

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Section: Optical Mesh Lattices In the Time Domainmentioning

confidence: 99%

Optical mesh lattices withPTsymmetry

Miri

Regensburger

Peschel³

et al. 2012

Phys. Rev. A

109

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“…This makes them valuable in quantum search algorithms [2] or even for general quantum computing [3]. Experiments on quantum walks range from realizations on trapped ions [4][5][6], to cold atoms in optical lattices [7][8][9], to light on an optical table [10][11][12][13][14][15], but there have been many other experimental proposals [16,17].…”

Section: Introductionmentioning

confidence: 99%

Localization, delocalization, and topological phase transitions in the one-dimensional split-step quantum walk

Rakovszky

Asbóth

2015

Phys. Rev. A

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Quantum walks are promising for information processing tasks because in regular graphs they spread quadratically more rapidly than random walks. Static disorder, however, can turn the tables: unlike random walks, quantum walks can suffer Anderson localization, with their wave function staying within a finite region even in the infinite time limit, with a probability exponentially close to 1. It is thus important to understand when a quantum walk will be Anderson localized and when we can expect it to spread to infinity even in the presence of disorder. In this work we analyze the response of a one-dimensional quantum walk-the split-step walk-to different forms of static disorder. We find that introducing static, symmetry-preserving disorder in the parameters of the walk leads to Anderson localization. In the completely disordered limit, however, a delocalization transition occurs, and the walk spreads subdiffusively to infinity. Using an efficient numerical algorithm, we calculate the bulk topological invariants of the disordered walk and find that the disorder-induced Anderson localization and delocalization transitions are governed by the topological phases of the quantum walk.

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“…Such regimes are important for example in systems in which energy or electrons are transferred from one loop or molecule to another, as they allow to generate quantum correlations between the different systems. Together with helping to understand and model the energy transfer and state transport processes in naturally occurring system, the recent experimental progress in creating quantum walks in various physical systems (NMR [39][40][41], cold ions [42,43], photons [44][45][46][47][48][49], and ultracold atoms [50]) will soon allow to study and engineer the processes we have described here in laboratory.…”

Section: Discussionmentioning

confidence: 99%

Noise-enhanced quantum transport on a closed loop using quantum walks

Chandrashekar

Busch

2014

Quantum Inf Process

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We study the effect of noise on the transport of a quantum state from a closed loop of n−sites with one of the sites as a sink. Using a discrete-time quantum walk dynamics, we demonstrate that the transport efficiency can be enhanced with noise when the number of sites in the loop is small and reduced when the number of sites in the loop grows. By using the concept of measurement induced disturbance we identify the regimes in which genuine quantum effects are responsible for the enhanced transport.

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Discrete Single-Photon Quantum Walks with Tunable Decoherence

Cited by 410 publications

References 33 publications

Optical mesh lattices withPTsymmetry

Optical mesh lattices withPTsymmetry

Localization, delocalization, and topological phase transitions in the one-dimensional split-step quantum walk

Noise-enhanced quantum transport on a closed loop using quantum walks

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