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We consider the problem of searching a general $d$-dimensional lattice of $N$ vertices for a single marked item using a continuous-time quantum walk. We demand locality, but allow the walk to vary periodically on a small scale. By…

Quantum Physics · Physics 2014-09-08 Andrew M. Childs , Yimin Ge

The evolution of a many-particle system on a one-dimensional lattice, subjected to a quantum walk can cause spatial entanglement in the lattice position, which can be exploited for quantum information/communication purposes. We demonstrate…

Quantum Physics · Physics 2010-05-21 Sandeep K. Goyal , C. M. Chandrashekar

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)…

The quantum walk dynamics obey the laws of quantum mechanics with an extra locality constraint, which demands that the evolution operator is local in the sense that the walker must visit the neighboring locations before endeavoring to…

Quantum Physics · Physics 2023-05-23 Caue F. T. Silva , Daniel Posner , Renato Portugal

The aim of this work is to develop a framework for realising quantum network algorithms with the use of prior knowledge about the structure of the network. We seek to obtain computational methods that allows us to locally determine network…

Quantum Physics · Physics 2017-01-30 Przemysław Sadowski

This comment is to correct the proof of optimality of quantum spatial search for Erd\H{o}s-R\'enyi graphs presented in `Spatial Search by Quantum Walk is Optimal for Almost all Graphs' (https://doi.org/10.1103/PhysRevLett.116.100501). The…

Quantum Physics · Physics 2020-09-29 Ryszard Kukulski , Adam Glos

Optimization problems become fundamentally challenging as the number of variables increases. Because the volume of the search space grows exponentially, classical algorithms frequently fail to locate the global minimum of non-convex…

Quantum Physics · Physics 2026-04-23 Dominik Soós , Marc Paterno , John Stenger , Nikos Chrisochoides

There exist two types of configurations of marked vertices on a two-dimensional grid, known as the {\it exceptional configurations}, which are hard to find by the discrete-time quantum walk algorithms. In this article, we provide a…

Quantum Physics · Physics 2025-07-04 Pulak Ranjan Giri

This paper introduces in detail a non-variational quantum algorithm designed to solve a wide range of combinatorial optimisation problems, including constrained problems and problems with non-binary variables. The algorithm returns optimal…

Quantum Physics · Physics 2024-08-14 Tavis Bennett , Lyle Noakes , Jingbo B. Wang

In typical discrete-time quantum walk algorithms, one measures the position of the walker while ignoring its internal spin/coin state. Rather than neglecting the information in this internal state, we show that additionally measuring it…

Quantum Physics · Physics 2016-10-20 Krišjānis Prūsis , Jevgēnijs Vihrovs , Thomas G. Wong

The Scattering Quantum Random Walk scheme has found success as a basis for search algorithms on highly symmetric graph structures. In this paper we examine its effectiveness at locating a specially marked vertex on square grid graphs,…

Quantum Physics · Physics 2019-01-23 Daniel Koch

A discrete-time Quantum Walk (QW) is essentially an operator driving the evolution of a single particle on the lattice, through local unitaries. Some QWs admit a continuum limit, leading to well-known physics partial differential equations,…

Quantum Physics · Physics 2018-06-20 Pablo Arrighi , Giuseppe Di Molfetta , Iván Márquez-Martín , Armando Pérez

In the paper, we investigated the influence of local and global interaction on the efficiency of continuous-time quantum spatial search. To do so, we analyzed numerically chimera graph, which is defined as 2D grid with each node replaced by…

Quantum Physics · Physics 2019-12-20 Adam Glos , Tomasz Januszek

Quantum walk search may exhibit phenomena beyond the intuition from a conventional random walk theory. One of such examples is exceptional configuration phenomenon -- it appears that it may be much harder to find any of two or more marked…

Quantum Physics · Physics 2021-01-13 Adam Glos , Nikolajs Nahimovs , Konstantin Balakirev , Kamil Khadiev

Adding self-loops at each vertex of a graph improves the performance of quantum walks algorithms over loopless algorithms. Many works approach quantum walks to search for a single marked vertex. In this article, we experimentally address…

Quantum Physics · Physics 2021-12-16 Luciano S. de Souza , Jonathan H. A. de Carvalho , Tiago A. E. Ferreira

This article presents a novel and succinct algorithmic framework via alternating quantum walks, unifying quantum spatial search, state transfer and uniform sampling on a large class of graphs. Using the framework, we can achieve exact…

Quantum Physics · Physics 2025-04-22 Qingwen Wang , Ying Jiang , Lvzhou Li

Quantum optimal control has enjoyed wide success for a variety of theoretical and experimental objectives. These favorable results have been attributed to advantageous properties of the corresponding control landscapes, which are free from…

Quantum magnetometry uses quantum resources to measure magnetic fields with precision and accuracy that cannot be achieved by its classical counterparts. In this paper, we propose a scheme for quantum magnetometry using discrete-time…

Quantum Physics · Physics 2024-03-28 Kunal Shukla , C. M. Chandrashekar

We show how a quantum walk can be used to find a marked edge or a marked complete subgraph of a complete graph. We employ a version of a quantum walk, the scattering walk, which lends itself to experimental implementation. The edges are…

Quantum Physics · Physics 2015-05-14 Mark Hillery , Daniel Reitzner , Vladimir Buzek

Quantum walk followed by some amplitude amplification technique has been successfully used to search for marked vertices on various graphs. Lackadaisical quantum walk can search for target vertices on graphs without the help of any…

Quantum Physics · Physics 2025-03-07 Pulak Ranjan Giri