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We discuss the description of eigenspace of a quantum walk model $U$ with an associating linear operator $T$ in abstract settings of quantum walk including the Szegedy walk on graphs. In particular, we provide the spectral mapping theorem…

Mathematical Physics · Physics 2016-04-05 Kaname Matsue , Osamu Ogurisu , Etsuo Segawa

This paper discusses the interplay of symmetries and stability in the analysis and control of nonlinear dynamical systems and networks. Specifically, it combines standard results on symmetries and equivariance with recent convergence…

Dynamical Systems · Mathematics 2015-05-20 Giovanni Russo , Jean-Jacques E. Slotine

We calculate the quantum states of regular polygons made of 1D quantum wires treating each polygon vertex as a scatterer. The vertex scattering matrix is analytically obtained from the model of a circular bend of a given angle of a 2D…

Mesoscale and Nanoscale Physics · Physics 2015-04-22 Cristian Estarellas , Llorenç Serra

The unitarity condition for scattering amplitudes in a non-anticommutative quantum field theory is investigated. The Cutkosky rules are shown to hold for Feynman diagrams in Euclidean momentum space and unitarity of amplitudes can be…

High Energy Physics - Theory · Physics 2007-05-23 J. W. Moffat

The quantification of the quantumness of a quantum ensemble has theoretical and practical significance in quantum information theory. We propose herein a class of measures of the quantumness of quantum ensembles using the unitary similarity…

Quantum Physics · Physics 2018-03-28 Xianfei Qi , Ting Gao , Fengli Yan

We consider random walks in a random environment which are generalized versions of well-known effective models for Mott variable-range hopping. We study the homogenized diffusion constant of the random walk in the one-dimensional case. We…

Probability · Mathematics 2009-09-29 P. Caputo , A. Faggionato

We investigate quantum symmetries in terms of their large-time stability with respect to perturbations of the Hamiltonian. We find a complete algebraic characterization of the set of symmetries robust against a single perturbation and we…

Quantum Physics · Physics 2025-03-25 Paolo Facchi , Marilena Ligabò , Vito Viesti

More than 15 years ago, a new approach to quantum mechanics was suggested, in which Hermiticity of the Hamiltonian was to be replaced by invariance under a discrete symmetry, the product of parity and time-reversal symmetry, $\mathcal{PT}$.…

High Energy Physics - Theory · Physics 2015-06-04 Kimball A. Milton , E. K. Abalo , Prachi Parashar , Nima Pourtolami , J. Wagner

Augmenting the unitary transformation which generates a quantum walk by a generalized phase gate G is a symmetry for both noisy and noiseless quantum walk on a line, in the sense that it leaves the position probability distribution…

Quantum Physics · Physics 2008-11-24 Subhashish Banerjee , R. Srikanth , C. M. Chandrashekar , Pranaw Rungta

Quantum walks, both discrete and continuous, serve as fundamental tools in quantum information processing with diverse applications. This work introduces a hybrid quantum walk model that integrates the coin mechanism of discrete walks with…

Quantum Physics · Physics 2025-09-12 Tianen Chen , Yun Shang

We consider the asymptotic behavior as $n\to\infty$ of the spectra of random matrices of the form \[\frac{1}{\sqrt{n-1}}\sum_{k=1}^{n-1}Z_{nk}\rho_n ((k,k+1)),\] where for each $n$ the random variables $Z_{nk}$ are i.i.d. standard Gaussian…

Probability · Mathematics 2009-06-11 Steven N. Evans

Quantum Markov networks are a generalization of quantum Markov chains to arbitrary graphs. They provide a powerful classification of correlations in quantum many-body systems---complementing the area law at finite temperature---and are…

Quantum Physics · Physics 2012-06-06 Winton Brown , David Poulin

Electronic transport through chaotic quantum dots exhibits universal, system independent, properties, consistent with random matrix theory. The quantum transport can also be rooted, via the semiclassical approximation, in sums over the…

Chaotic Dynamics · Physics 2013-03-06 Gregory Berkolaiko , Jack Kuipers

Given a quantum permutation group $G\subset S_N^+$, with orbits having the same size $K$, we construct a universal matrix model $\pi:C(G)\to M_K(C(X))$, having the property that the images of the standard coordinates $u_{ij}\in C(G)$ are…

Operator Algebras · Mathematics 2018-06-05 Teodor Banica , Amaury Freslon

In the study of quantum computation, data is represented in terms of linear operators which form a generalized model of probability, and computations are most commonly described as products of unitary transformations, which are the…

Quantum Physics · Physics 2008-12-16 Jonathan Robert Niel de Beaudrap

We present a method, based on commutator methods, for the spectral analysis of uniquely ergodic dynamical systems. When applicable, it leads to the absolute continuity of the spectrum of the corresponding unitary operators. As an…

Dynamical Systems · Mathematics 2019-02-20 Rafael Tiedra de Aldecoa

In this paper, we investigate the spectral stability of periodic traveling waves for a cubic-quintic and double dispersion equation. Using the quadrature method we find explict periodic waves and we also present a characterization for all…

Analysis of PDEs · Mathematics 2023-07-13 Fábio Natali , Thiago P. de Andrade

Let A and B be normal matrices with coefficients that are continuous complex-valued functions on a topological space X that has the homotopy type of a CW complex, and suppose these matrices have the same distinct eigenvalues at each point…

Operator Algebras · Mathematics 2018-12-31 Greg Friedman , Efton Park

We provide an analysis of the classic Kuramoto model of coupled nonlinear oscillators that goes beyond the existing results for all-to-all networks of identical oscillators. Our work is applicable to oscillator networks of arbitrary…

Optimization and Control · Mathematics 2007-05-23 Ali Jadbabaie , Nader Motee , Mauricio Barahona

We consider quantum walks on the cycle in the non-stationary case where the `coin' operation is allowed to change at each time step. We characterize, in algebraic terms, the set of possible state transfers and prove that, as opposed to the…

Quantum Physics · Physics 2009-11-13 Domenico D'Alessandro , Gianfranco Parlangeli , Francesca Albertini