English

Quantum walks with sequential aperiodic jumps

Quantum Physics 2020-07-30 v3 Statistical Mechanics

Abstract

We analyze a set of discrete-time quantum walks for which the displacements on a chain follow binary aperiodic jumps according to three paradigmatic sequences: Fibonacci, Thue-Morse and Rudin-Shapiro. We use a generalized Hadamard coin C^H\widehat C_{H} as well as a generalized Fourier coin C^K\widehat C_{K}. We verify the QW experiences a slowdown of the wavepacket spreading --- σ2(t)tα\sigma ^2 (t) \sim t^\alpha --- by the aperiodic jumps whose exponent, α\alpha, depends on the type of aperiodicity. Additional aperiodicity-induced effects also emerge, namely: (i) while the superdiffusive regime (1<α<21<\alpha<2) is predominant, α\alpha displays an unusual sensibility with the type of coin operator where the more pronounced differences emerge for the Rudin-Shapiro and random protocol; (ii) even though the angle θ\theta of the coin operator is homogeneous in space and time, there is a nonmonotonic dependence of α\alpha with θ\theta. Fingerprints of the aperiodicity in the hoppings are also found when additional distributional measures such as Shannon entropy, IPR, Jensen-Shannon dissimilarity, and kurtosis are computed. Finally, we argue the spin-lattice entanglement is enhanced by aperiodic jumps.

Keywords

Cite

@article{arxiv.1910.02254,
  title  = {Quantum walks with sequential aperiodic jumps},
  author = {Marcelo A. Pires and Sílvio M. Duarte Queirós},
  journal= {arXiv preprint arXiv:1910.02254},
  year   = {2020}
}

Comments

Updated version, close to the published one

R2 v1 2026-06-23T11:35:15.878Z