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Several well-known results from the random matrix theory, such as Wigner's law and the Marchenko--Pastur law, can be interpreted (and proved) in terms of non-backtracking walks on a certain graph. Orthogonal polynomials with respect to the…

Mathematical Physics · Physics 2009-11-13 Sasha Sodin

For a continuous-time quantum walk on a line the variance of the position observable grows quadratically in time, whereas, for its classical counterpart on the same graph, it exhibits a linear, diffusive, behaviour. A quantum walk, thus,…

Quantum Physics · Physics 2008-01-30 Diego de Falco , Dario Tamascelli

Quantum computing has the potential to solve complex problems faster and more efficiently than classical computing. It can achieve speedups by leveraging quantum phenomena like superposition, entanglement, and tunneling. Quantum walks (QWs)…

We introduce quantized bipartite walks, compute their spectra, generalize the algorithms of Grover \cite{g} and Ambainis \cite{amb03} and interpret them as quantum walks with memory. We compare the performance of walk based classical and…

Quantum Physics · Physics 2007-05-23 Mario Szegedy

It is demonstrated that in gate-based quantum computing architectures quantum walk is a natural mathematical description of quantum gates. It originates from field-matter interaction driving the system, but is not attached to specific qubit…

Quantum Physics · Physics 2020-05-08 Dmitry Solenov

Quantum walk (QW) provides a versatile tool to study fundamental physics and also to make a variety of practical applications. We here start with the recent idea of {\it nonlinear} QW and show that introducing {\it nonlinearity} to QW can…

Quantum Physics · Physics 2015-12-29 Chang-Woo Lee , Paweł Kurzyński , Hyunchul Nha

We investigate quantum walks in multiple dimensions with different quantum coins. We augment the model by assuming that at each step the amplitudes of the coin state are multiplied by random phases. This model enables us to study in detail…

Quantum Physics · Physics 2009-11-13 Jozef Kosik , Vladimir Buzek , Mark Hillery

We show that the entanglement between the internal (spin) and external (position) degrees of freedom of a qubit in a random (dynamically disordered) one-dimensional discrete time quantum random walk (QRW) achieves its maximal possible value…

Quantum Physics · Physics 2013-11-04 Rafael Vieira , Edgard P. M. Amorim , Gustavo Rigolin

We study the transport properties of continuous-time quantum walks (CTQW) over finite two-dimensional structures with a given number of randomly placed bonds and with different aspect ratios (AR). Here, we focus on the transport from, say,…

Quantum Physics · Physics 2015-06-17 Anastasiia Anishchenko , Alexander Blumen , Oliver Muelken

The quantum circuit model is the most commonly used model for implementing quantum computers and quantum neural networks whose essential tasks are to realize certain unitary operations. The circuit model usually implements a desired unitary…

Quantum Physics · Physics 2023-04-14 Jia-Yi Lin , Xin-Yu Li , Yu-Hao Shao , Wei Wang , Shengjun Wu

A quantum walk on a toral phase space involving translations in position and its conjugate momentum is studied in the simple context of a coined walker in discrete time. The resultant walk, with a family of coins parametrized by an angle is…

Quantum Physics · Physics 2018-09-26 Sivaprasad Omanakuttan , Arul Lakshminarayan

Quadratic matrix equations of the kind $A_1X^2+A_0X+A_{-1}=X$ are encountered in the analysis of Quasi--Birth-Death stochastic processes where the solution of interest is the minimal nonnegative solution $G$. In many queueing models,…

Numerical Analysis · Mathematics 2021-01-25 Dario A. Bini , Beatrice Meini , Jie Meng

We present numerical study of a model of quantum walk in periodic potential on the line. We take the simple view that different potentials affect differently the way the coin state of the walker is changed. For simplicity and definiteness,…

Quantum Physics · Physics 2015-06-16 C. -I. Chou , C. -L. Ho

We present a detailed circuit implementation of Szegedy's quantization of the Metropolis-Hastings walk. This quantum walk is usually defined with respect to an oracle. We find that a direct implementation of this oracle requires costly…

Quantum Physics · Physics 2020-07-01 Jessica Lemieux , Bettina Heim , David Poulin , Krysta Svore , Matthias Troyer

Quantum walks have wide applications in quantum information, such as universal quantum computation, so it is important to explore properties of quantum walks thoroughly. We propose a novel method to implement discrete-time quantum walks…

Quantum Physics · Physics 2022-06-09 Qi-Ping Su , Shi-Chao Wang , Yan Chi , Yong-Nan Sun , Li Yu , Zhe Sun , Franco Nori , Chui-Ping Yang

We analyze the probability distributions of the quantum walks induced from Markov chains by Szegedy (2004). The first part of this paper is devoted to the quantum walks induced from finite state Markov chains. It is shown that the…

Quantum Physics · Physics 2017-12-19 Radhakrishnan Balu , Chaobin Liu , Salvador E. Venegas-Andraca

Quantum walk serves as a versatile tool for universal quantum computing and algorithmic research. However, the implementation of discrete-time quantum walks (DTQWs) with superconducting circuits is still constrained by some limitations such…

We present an efficient general method for realizing a quantum walk operator corresponding to an arbitrary sparse classical random walk. Our approach is based on Grover and Rudolph's method for preparing coherent versions of efficiently…

Quantum Physics · Physics 2013-06-12 Chen-Fu Chiang , Daniel Nagaj , Pawel Wocjan

This work presents a novel approach to compute the eigenvalues of non-Hermitian matrices using an enhanced shifted QR algorithm. The existing QR algorithms fail to converge early in the case of non-hermitian matrices, and our approach shows…

Numerical Analysis · Mathematics 2025-10-16 Chahat Ahuja , Partha Chowdhury , Subhashree Mohapatra

In this work we focus on the notion of quantum hitting time for discrete-time Szegedy quantum walks, compared to its classical counterpart. Under suitable hypotheses, quantum hitting time is known to be of the order of the square root of…

Quantum Physics · Physics 2024-09-18 P. Boito , G. M. Del Corso