Quantum recurrence of a subspace and operator-valued Schur functions

J Bourgain, FA Grünbaum, L Velázquez… - … in Mathematical Physics, 2014 - Springer
A notion of monitored recurrence for discrete-time quantum processes was recently
introduced in Grünbaum et al.(Commun Math Phys (2), 320: 543–569, 2013) taking the …

Partition-based discrete-time quantum walks

N Konno, R Portugal, I Sato, E Segawa - Quantum Information Processing, 2018 - Springer
We introduce a family of discrete-time quantum walks, called two-partition model, based on
two equivalence-class partitions of the computational basis, which establish the notion of …

[HTML][HTML] Anderson localization for electric quantum walks and skew-shift CMV matrices

C Cedzich, AH Werner - Communications in Mathematical Physics, 2021 - Springer
We consider the spectral and dynamical properties of one-dimensional quantum walks
placed into homogenous electric fields according to a discrete version of the minimal …

Limit distributions of three-state quantum walks: the role of coin eigenstates

M Štefaňák, I Bezděková, I Jex - Physical Review A, 2014 - APS
We analyze two families of three-state quantum walks which show the localization effect. We
focus on the role of the initial coin state and its coherence in controlling the properties of the …

Singular continuous Cantor spectrum for magnetic quantum walks

C Cedzich, J Fillman, T Geib, AH Werner - Letters in Mathematical Physics, 2020 - Springer
In this note, we consider a physical system given by a two-dimensional quantum walk in an
external magnetic field. In this setup, we show that both the topological structure and its type …

An index theorem for split-step quantum walks

Y Matsuzawa - Quantum Information Processing, 2020 - Springer
Split-step quantum walks are models of supersymmetric quantum walk, and thus, their
Witten indices can be defined. We prove that the Witten index of a split-step quantum walk …

The uniform measure for discrete-time quantum walks in one dimension

N Konno - Quantum information processing, 2014 - Springer
The uniform measure for discrete-time quantum walks in one dimension | SpringerLink Skip to
main content Advertisement SpringerLink Log in Menu Find a journal Publish with us Search …

Eigenvalues of two-phase quantum walks with one defect in one dimension

C Kiumi, K Saito - Quantum Information Processing, 2021 - Springer
We study space-inhomogeneous quantum walks (QWs) on the integer lattice which we
assign three different coin matrices to the positive part, the negative part, and the origin …

[HTML][HTML] A generalization of Schur functions: applications to Nevanlinna functions, orthogonal polynomials, random walks and unitary and open quantum walks

FA Grünbaum, L Velázquez - Advances in Mathematics, 2018 - Elsevier
Recent work on return properties of quantum walks (the quantum analogue of random
walks) has identified their generating functions of first returns as Schur functions. This is …

Feynman checkers: towards algorithmic quantum theory

M Skopenkov, A Ustinov - arXiv preprint arXiv:2007.12879, 2020 - arxiv.org
We survey and develop the most elementary model of electron motion introduced by R.
Feynman. In this game, a checker moves on a checkerboard by simple rules, and we count …