Diverse tunable dynamics of two quantum random walkers

Shrabanti Dhar; Abdul Khaleque; Tushar Kanti Bose

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arXiv · 1909.08527

Diverse tunable dynamics of two quantum random walkers

Shrabanti Dhar·Abdul Khaleque·Tushar Kanti Bose

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Abstract

Quantum walk research has mainly focused on evolutions due to repeated applications of time-independent unitary coin operators. However, the idea of controlling the single particle evolution using time-dependent unitary coins has still been a subject of multiple studies as it not only hosts interesting possibilities for quantum information processing but also opens a much richer array of phenomena including static and dynamic localizations. So far, such studies have been performed only for single quantum walkers. In case of multi-walker systems, time-dependent coins may generate measurable phenomena not described by the single-particle model, due to entanglement and interaction among the walkers. In this context, we present here a thorough numerical study of an one dimensional system of two quantum walkers exhibiting rich collective dynamics controlled by simple time-dependent unitary coins proposed in [Phys. Rev. A \textbf{80}, 042332(2009)] and [Phys. Rev. A \textbf{73},062304(2006)]. We study how the interplay of coin time-dependence, simple interaction schemes, entanglement and the relative phase between the coin states of the particles influences the evolution of the quantum walk. The results show that the system offers a rich variety of collective dynamical behavior while being controlled by time dependent coins. In particular, we find and characterize fascinating two-body localization phenomena with tunable quasiperiodic dynamics of correlations and entanglements which are quantities of quantum origin.

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Shrabanti Dhar, Abdul Khaleque, Tushar Kanti Bose. 2019-09-17. Diverse tunable dynamics of two quantum random walkers. https://arxiv.org/abs/1909.08527

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