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Through introducing controlled alternative quantum walks, we present controlled alternate quantum walks (CAQW) based quantum hash function. CAQW based quantum hash function have excellent security, outstanding statistical performance and…

Quantum Physics · Physics 2017-07-25 Dan Li , Yu-Guang Yang , Jing-Lin Bi , Jia-Bin Yuan , Juan Xu

We predict and theoretically study in detail the ratchet effect for the spectral magnetization of periodic discrete time quantum walks (DTQWs) --- a repetition of a sequence of $m$ different DTQWs. These generalized DTQWs are achieved by…

Quantum Physics · Physics 2020-04-08 A. Mallick , M. V. Fistul , P. Kaczynska , S. Flach

Even after decades of research the problem of first passage time statistics for quantum dynamics remains a challenging topic of fundamental and practical importance. Using a projective measurement approach, with a sampling time $\tau$, we…

Statistical Mechanics · Physics 2017-04-05 Harel Friedman , David A. Kessler , Eli Barkai

A continuous-time quantum walk (CTQW) is sedentary if the return probability in the starting vertex is close to one at all times. Recent results imply that, when starting from a maximal degree vertex, the CTQW dynamics generated by the…

Quantum Physics · Physics 2023-06-12 Massimo Frigerio , Matteo G. A. Paris

We study the classical and quantum transport processes on some finite networks and model them by continuous-time random walks (CTRW) and continuous-time quantum walks (CTQW), respectively. We calculate the classical and quantum transition…

Quantum Physics · Physics 2011-04-05 S. Salimi , R. Radgohar , M. M. Soltanzadeh

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 formulate continuous time quantum walks (CTQW) in a discrete quantum mechanical phase space. We define and calculate the Wigner function (WF) and its marginal distributions for CTQWs on circles of arbitrary length $N$. The WF of the CTQW…

Quantum Physics · Physics 2009-11-11 Oliver Muelken , Alexander Blumen

We investigate the statistics of the first detected passage time of a quantum walk. The postulates of quantum theory, in particular the collapse of the wave function upon measurement, reveal an intimate connection between the wave function…

Statistical Mechanics · Physics 2020-09-21 H. Friedman , D. A. Kessler , E. Barkai

Discrete-time quantum walks, quantum generalizations of classical random walks, provide a framework for quantum information processing, quantum algorithms and quantum simulation of condensed matter systems. The key property of quantum…

Quantum Physics · Physics 2023-06-07 Rostislav Duda , Moein N. Ivaki , Isac Sahlberg , Kim Pöyhönen , Teemu Ojanen

We introduce a discrete-time quantum random walk (QRW) framework for spatial epidemic modelling on a two-dimensional square lattice and compare its dynamics to classical random-walk SIR models. In our model, each infected site spawns a…

Quantum Physics · Physics 2025-09-15 Sayan Manna , Nikhil Kowshik , Sudebkumar Prasant Pal

Quantum walks (QW) are of crucial importance in the development of quantum information processing algorithms. Recently, several quantum algorithms have been proposed to implement network analysis, in particular to rank the centrality of…

Quantum Physics · Physics 2021-01-04 Tong Wu , J. A. Izaac , Zi-Xi Li , Kai Wang , Zhao-Zhong Chen , Shining Zhu , J. B. Wang , Xiao-Song Ma

The propagation by continuous time quantum walks (CTQWs) on one-dimensional lattices shows structures in the transition probabilities between different sites reminiscent of quantum carpets. For a system with periodic boundary conditions, we…

Quantum Physics · Physics 2009-11-11 Oliver Muelken , Alexander Blumen

We present a detailed analysis of continuous time quantum walks (CTQW) with both position and transition defects defined at a single point in the line. Analytical solutions of both traveling waves or bound states are obtained, which provide…

Quantum Physics · Physics 2015-09-08 Zhi-Jian Li , J. B. Wang

Quantum walk (QW), which is considered as the quantum counterpart of the classical random walk (CRW), is actually the quantum extension of CRW from the single-coin interpretation. The sequential unitary evolution engenders correlation…

Quantum Physics · Physics 2020-03-11 Jin-Fu Chen , Yu-Han Ma , Chang-Pu Sun

A new family of discrete-time quantum walks (DTQWs) on the line with an exact discrete $U(N)$ gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac…

Quantum Physics · Physics 2025-02-28 Pablo Arnault , Giuseppe Di Molfetta , Marc Brachet , Fabrice Debbasch

A quantum walk is the quantum analogue of a random walk. While it is relatively well understood how quantum walks can speed up random walk hitting times, it is a long-standing open question to what extent quantum walks can speed up the…

Quantum Physics · Physics 2024-02-13 Simon Apers , Laurent Miclo

Quantum walks are standard tools for searching graphs for marked vertices, and they often yield quadratic speedups over a classical random walk's hitting time. In some exceptional cases, however, the system only evolves by sign flips,…

Quantum Physics · Physics 2017-05-05 Thomas G. Wong , Raqueline A. M. Santos

We introduce a novel time-energy uncertainty relation within the context of restarts in monitored quantum dynamics. Initially, we investigate the concept of ``first hitting time'' in quantum systems using an IBM quantum computer and a…

Statistical Mechanics · Physics 2025-01-07 Ruoyu Yin , Qingyuan Wang , Sabine Tornow , Eli Barkai

Recently, quantized versions of random walks have been explored as effective elements for quantum algorithms. In the simplest case of one dimension, the theory has remained divided into the discrete-time quantum walk and the continuous-time…

Quantum Physics · Physics 2009-11-13 Frederick W. Strauch

Quantum algorithms have demonstrated provable speedups over classical counterparts, yet establishing a comprehensive theoretical framework to understand the quantum advantage remains a core challenge. In this work, we decode the quantum…

Quantum Physics · Physics 2025-11-11 Si-Qi Zhou , Jin-Min Liang , Ziheng Ding , Zhihua Chen , Shao-Ming Fei , Zhihao Ma