English

Multiple transitions between normal and hyperballistic diffusion in quantum walks with time-dependent jumps

Quantum Physics 2020-07-21 v1 Statistical Mechanics

Abstract

We extend to the gamut of functional forms of the probability distribution of the time-dependent step-length a previous model dubbed Elephant Quantum Walk, which considers a uniform distribution and yields hyperballistic dynamics where the variance grows cubicly with time, σ2t3\sigma ^2 \propto t^3, and a Gaussian for the position of the walker. We investigate this proposal both locally and globally with the results showing that the time-dependent interplay between interference, memory and long-range hopping leads to multiple transitions between dynamical regimes, namely ballistic \rightarrow diffusive \rightarrow superdiffusive \rightarrow ballistic \rightarrow hyperballistic for non-hermitian coin whereas the first diffusive regime is quelled for implementations using the Hadamard coin. In addition, we observe a robust asymptotic approach to maximal coin-space entanglement.

Keywords

Cite

@article{arxiv.1907.12696,
  title  = {Multiple transitions between normal and hyperballistic diffusion in quantum walks with time-dependent jumps},
  author = {Marcelo A. Pires and Giuseppe Di Molfetta and Sílvio M. Duarte Queirós},
  journal= {arXiv preprint arXiv:1907.12696},
  year   = {2020}
}

Comments

11 pages, 11 figures

R2 v1 2026-06-23T10:34:19.848Z