Characterization of anomalous diffusion in one-dimensional quantum walks

Hegde, AS and Chandrashekar, CM (2022) Characterization of anomalous diffusion in one-dimensional quantum walks. In: Journal of Physics A: Mathematical and Theoretical, 55 (23).

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Abstract

Quantum walks are known to propagate quadratically faster than their classical counterparts and are used to model dynamics in various quantum systems. The spread of the quantum walk in position space shows anomalous diffusion behavior. By controlling the action of quantum coin operation on the corresponding coin degree of freedom of the walker, one can demonstrate control over the diffusion behavior. In this work, we report different forms of coin operations on quantum walks exhibiting anomalous diffusion behavior. Homogeneous and accelerated quantum walks display superdiffusive behavior, whereas uncorrelated static and dynamic disorders in the evolution induce strong and weak localization of the particle indicating subdiffusive and normal diffusive behavior. The role played by the interference effects in the spreading of the walker has remained elusive and our aim in this work is to present the interplay between quantum coherence and mean squared displacement of the walker. We employ two reliable measures of coherence for conclusively establishing the role of quantum interference as the driving force behind the anomalous diffusive behavior in the dynamics of quantum walks. © 2022 IOP Publishing Ltd.

Item Type:	Journal Article
Publication:	Journal of Physics A: Mathematical and Theoretical
Publisher:	Institute of Physics
Additional Information:	The copyright for this article belongs to the Institute of Physics.
Keywords:	anomalous diffusion; coherence; quantum walks
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	15 Jun 2022 09:48
Last Modified:	15 Jun 2022 09:48
URI:	https://eprints.iisc.ac.in/id/eprint/73596

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