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Grover's algorithm for quantum searching is generalized to deal with arbitrary initial complex amplitude distributions. First order linear difference equations are found for the time evolution of the amplitudes of the marked and unmarked…

Quantum Physics · Physics 2016-09-08 Eli Biham , Ofer Biham , David Biron , Markus Grassl , Daniel A. Lidar

This paper presented two general quantum search algorithms. We derived the iterated formulas and the simpler approximate formulas and the precise formula for the amplitude in the desired state. A mathematical proof of Grover's algorithm…

Quantum Physics · Physics 2009-11-07 Dafa Li , Xinxin Li

Grover's quantum search algorithm can be formulated as a quantum particle randomly walking on the (highly symmetric) complete graph, with one vertex marked by a nonzero potential. From an initial equal superposition, the state evolves in a…

Quantum Physics · Physics 2014-05-30 Jonatan Janmark , David A. Meyer , Thomas G. Wong

Grover's quantum algorithm improves any classical search algorithm. We show how random Gaussian noise at each step of the algorithm can be modelled easily because of the exact recursion formulas available for computing the quantum amplitude…

Quantum Physics · Physics 2009-10-31 B. Pablo-Norman , M. Ruiz-Altaba

The search problem is to find a state satisfying certain properties out of a given set. Grover's algorithm drives a quantum computer from a prepared initial state to the target state and solves the problem quadratically faster than a…

Quantum Physics · Physics 2009-11-13 Avatar Tulsi

Understanding algorithmic error accumulation in quantum simulation is crucial due to its fundamental significance and practical applications in simulating quantum many-body system dynamics. Conventional theories typically apply the triangle…

Quantum Physics · Physics 2024-11-11 Boyang Chen , Jue Xu , Qi Zhao , Xiao Yuan

We formulate Grover's unstructured search algorithm as a chiral quantum walk, where transitioning in one direction has a phase conjugate to transitioning in the opposite direction. For small phases, this breaking of time-reversal symmetry…

Quantum Physics · Physics 2015-09-22 Thomas G. Wong

It is found that Grover's quantum search algorithm is not robust against phase inversion and Hadmard transformation inaccuracies. Imperfect phase inversions and Hadmard-Walsh transformations in Grover's quantum search algorithm lead to…

Quantum Physics · Physics 2007-05-23 Gui Lu Long , Yan Song Li , Wei Lin Zhang , Chang Cun Tu

Quantum computing (QC) emulators, which simulate quantum algorithms on classical hardware, are indispensable platforms for testing quantum algorithms before scalable quantum computers become widely available. A critical challenge in QC…

Quantum Physics · Physics 2025-04-03 Seonghyun Choi , Kyeongwon Lee , Jongin Choi , Woojoo Lee

The equivalence principle, being one of the building blocks of general relativity, seems to be also crucial for analysis of quantum effects in gravity. In this paper we consider the question if the equivalence principle has to hold for…

Quantum Physics · Physics 2023-12-06 Marcin Nowakowski

Variational quantum time evolution allows us to simulate the time dynamics of quantum systems with near-term compatible quantum circuits. Due to the variational nature of this method the accuracy of the simulation is a priori unknown. We…

Quantum Physics · Physics 2023-10-25 Christa Zoufal , David Sutter , Stefan Woerner

The translation of Grover's search algorithm from its standard version, designed for implementation on a single quantum system amenable to projective measurements, into one suitable for an ensemble of quantum computers, whose outputs are…

Quantum Physics · Physics 2009-11-07 David Collins

We establish a lower bound concerning the computational complexity of Grover's algorithms on fractal networks. This bound provides general predictions for the quantum advantage gained for searching unstructured lists. It yields a…

Statistical Mechanics · Physics 2018-07-19 Stefan Boettcher , Shanshan Li , Tharso D. Fernandes , Renato Portugal

Grover's quantum search algorithm, involving a large number of qubits, is highly sensitive to errors in the physical implementation of the unitary operators. This poses an intrinsic limitation to the size of the database that can be…

Quantum Physics · Physics 2009-12-22 Avik Mitra , Avatar Tulsi , Anil Kumar

We recast Grover's generalised search algorithm in a geometric language even when the states are not approximately orthogonal. We provide a possible search algorithm based on an arbitrary unitary transformation which can speed up the steps…

Quantum Physics · Physics 2007-05-23 Arun Kumar Pati

Existence of a minimal measurable length and an upper bound for the momentum fluctuations are the casting reasons for generalization of uncertainty principle and then reformulation of Hilbert space representation of quantum mechanics. In…

General Relativity and Quantum Cosmology · Physics 2016-11-29 N. Sadeghnezhad

The execution of Grover's quantum search algorithm needs rather limited resources without much fine tuning. Consequently, the algorithm can be implemented in a variety of physical set-ups, which involve wave dynamics but may not need other…

Quantum Physics · Physics 2021-07-08 Apoorva D. Patel

The Grover quantum search algorithm is generalized to deal with an arbitrary mixed initial state. The probability to measure a marked state as a function of time is calculated, and found to depend strongly on the specific initial state. The…

Quantum Physics · Physics 2007-05-23 Eli Biham , Dan Kenigsberg

In this paper, we study decoherence in Grover's quantum search algorithm using a perturbative method. We assume that each two-state system (qubit) that belongs to a register suffers a phase flip error (\sigma_{z} error) with probability p…

Quantum Physics · Physics 2011-01-21 Hiroo Azuma

Coherence plays a very important role in Grover search algorithm (GSA). In this paper, we define the normalization coherence N(C), where C is a coherence measurement. In virtue of the constraint of large N and Shannon's maximum entropy…

Quantum Physics · Physics 2022-06-22 Minghua Pan , Haozhen Situ , Shenggen Zheng