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Grover's quantum search algorithm provides a quadratic speedup over the classical one. The computational complexity is based on the number of queries to the oracle. However, depth is a more modern metric for noisy intermediate-scale quantum…

Quantum Physics · Physics 2020-03-31 Kun Zhang , Vladimir E. Korepin

We demonstrate an implementation of the hitting time of a discrete time quantum random walk on cubelike graphs using IBM's Qiskit platform. Our implementation is based on efficient circuits for the Grover and Shift operators. We verify the…

Quantum Physics · Physics 2021-09-01 Jaideep Mulherkar , Rishikant Rajdeepak , V Sunitha

Grover search is a renowned quantum search algorithm that leverages quantum superposition to find a marked item with quadratic speedup. However, when implemented on Noisy Intermediate-scale Quantum (NISQ) hardware, the required repeated…

Quantum Physics · Physics 2023-04-11 Chen-Yu Liu

$ $In its usual form, Grover's quantum search algorithm uses $O(\sqrt{N})$ queries and $O(\sqrt{N} \log N)$ other elementary gates to find a solution in an $N$-bit database. Grover in 2002 showed how to reduce the number of other gates to…

Quantum Physics · Physics 2016-10-24 Srinivasan Arunachalam , Ronald de Wolf

We address the dynamics of continuous-time quantum walk (CTQW) on planar 2D lattice graphs, i.e. those forming a regular tessellation of the Euclidean plane (triangular, square, and honeycomb lattice graphs). We first consider the free…

Quantum Physics · Physics 2020-04-01 Luca Razzoli , Matteo G. A. Paris , Paolo Bordone

In a recent work by Novo et al. (Sci. Rep. 5, 13304, 2015), the invariant subspace method was applied to the study of continuous-time quantum walk (CTQW). The method helps to reduce a graph into a simpler version that allows more…

Quantum Physics · Physics 2018-02-22 Chen-Fu Chiang , Chang-Yu Hsieh

Quantum computation, in particular Grover's algorithm, has aroused a great deal of interest since it allows for a quadratic speedup to be obtained in search procedures. Classical search procedures for an $N$ element database require at most…

Data Structures and Algorithms · Computer Science 2015-02-09 Luís Tarrataca , Andreas Wichert

Quantum random walk finds application in efficient quantum algorithms as well as in quantum network theory. Here we study the mixing time of a discrete quantum walk over a square lattice in presence percolation and decoherence. We consider…

Quantum Physics · Physics 2018-09-12 Arkaprabha Ghosal , Prasenjit Deb

Grover's unstructured search algorithm is one of the best examples to date for the superiority of quantum algorithms over classical ones. Its applicability, however, has been questioned by many due to its oracular nature. We propose a…

Quantum Physics · Physics 2017-08-21 Itay Hen

Recently several quantum search algorithms based on quantum walks were proposed. Those algorithms differ from Grover's algorithm in many aspects. The goal is to find a marked vertex in a graph faster than classical algorithms. Since the…

Quantum Physics · Physics 2012-05-18 G. Abal , R. Donangelo , F. L. Marquezino , A. C. Oliveira , R. Portugal

A discrete time quantum walk is known to be the single-particle sector of a quantum cellular automaton. Searching in this mathematical framework has interested the community since a long time. However, most results consider spatial search…

Quantum Physics · Physics 2023-12-27 Mathieu Roget , Giuseppe Di Molfetta

L. K. Grover's search algorithm in quantum computing gives an optimal, quadratic speedup in the search for a single object in a large unsorted database. In this paper, we generalize Grover's algorithm in a Hilbert-space framework for both…

Quantum Physics · Physics 2007-05-23 Goong Chen , Stephen A. Fulling , Jeesen Chen

Quantum algorithms and circuits can, in principle, outperform the best non-quantum (classical) techniques for some hard computational problems. However, this does not necessarily lead to useful applications. To gauge the practical…

Quantum Physics · Physics 2007-05-23 George F. Viamontes , Igor L. Markov , John P. Hayes

Sufficiently strong inter-site interactions in extended-Hubbard and XXZ spin models result in dynamically-bound clusters at neighboring sites. We show that the dynamics of these clusters in two-dimensional lattices is remarkably different…

Quantum Gases · Physics 2021-04-28 Wei-Han Li , Arya Dhar , Xiaolong Deng , Luis Santos

A quantum computer encodes information in quantum states and runs quantum algorithms to surpass the classical counterparts by exploiting quantum superposition and quantum correlation. Grover's quantum search algorithm is a typical quantum…

Quantum Physics · Physics 2023-08-23 Yutong Huang , Shengshi Pang

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

We report on an experiment on Grover's quantum search algorithm showing that {\em classical waves} can search a $N$-item database as efficiently as quantum mechanics can. The transverse beam profile of a short laser pulse is processed…

Quantum Physics · Physics 2016-09-08 N. Bhattacharya , H. B. van Linden van den Heuvell , R. J. C. Spreeuw

A randomly walking quantum particle searches in Grover's $\Theta(\sqrt{N})$ iterations for a marked vertex on the complete graph of $N$ vertices by repeatedly querying an oracle that flips the amplitude at the marked vertex, scattering by a…

Quantum Physics · Physics 2015-09-22 Andris Ambainis , Thomas G. Wong

Spatial search by discrete-time quantum walk can find a marked node on any ergodic, reversible Markov chain $P$ quadratically faster than its classical counterpart, i.e.\ in a time that is in the square root of the hitting time of $P$.…

Quantum Physics · Physics 2020-09-02 Shantanav Chakraborty , Leonardo Novo , Jérémie Roland

We present a quantum algorithm for solving perfect mazes by casting the pathfinding task as a structured search problem. Building on Grover's amplitude amplification, the algorithm encodes all candidate paths in superposition and evaluates…

Quantum Physics · Physics 2025-07-31 Michelle L. Wu