English
Related papers

Related papers: Quantum Counting

200 papers

Grover's algorithm, orginally conceived as a means of searching an unordered database, can also be used to extract solutions from the result sets generated by quantum computations. The Grover algorithm exploits the concept of an oracle…

Quantum Physics · Physics 2024-11-19 Fintan M. Bolton

Quantum amplitude estimation is a key sub-routine of a number of quantum algorithms with various applications. We propose an adaptive algorithm for interval estimation of amplitudes. The quantum part of the algorithm is based only on…

Quantum Physics · Physics 2022-06-20 Yunpeng Zhao , Haiyan Wang , Kuai Xu , Yue Wang , Ji Zhu , Feng Wang

Quantum computing has noteworthy speedup over classical computing by taking advantage of quantum parallelism, i.e., the superposition of states. In particular, quantum search is widely used in various computationally hard problems. Grover's…

Quantum Physics · Physics 2021-03-29 Ji Liu , Huiyang Zhou

Amplitude Amplification -- a key component of Grover's Search algorithm -- uses an iterative approach to systematically increase the probability of one or multiple target states. We present novel strategies to enhance the amplification…

Quantum Physics · Physics 2021-06-22 Austin Gilliam , Marco Pistoia , Constantin Gonciulea

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

We present a quantum algorithmic routine that extends the realm of Grover-based heuristics for tackling combinatorial optimization problems with arbitrary efficiently computable objective and constraint functions. Building on previously…

Quantum Physics · Physics 2025-12-10 Sören Wilkening

Quantum computers can execute algorithms that sometimes dramatically outperform classical computation. Undoubtedly the best-known example of this is Shor's discovery of an efficient quantum algorithm for factoring integers, whereas the same…

Quantum Physics · Physics 2017-08-23 Wim van Dam , Yoshitaka Sasaki

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

Approximate Counting refers to the problem where we are given query access to a function $f : [N] \to \{0,1\}$, and we wish to estimate $K = #\{x : f(x) = 1\}$ to within a factor of $1+\epsilon$ (with high probability), while minimizing the…

Quantum Physics · Physics 2020-10-12 Ramgopal Venkateswaran , Ryan O'Donnell

Grover's algorithm, a well-know quantum search algorithm, allows one to find the correct item in a database, with quadratic speedup. In this paper we adapt Grover's algorithm to the problem of finding a correct answer to a natural language…

Quantum Physics · Physics 2022-01-28 A. D. Correia , M. Moortgat , H. T. C. Stoof

Run-times of quantum algorithms are often studied via an asymptotic, worst-case analysis. Whilst useful, such a comparison can often fall short: it is not uncommon for algorithms with a large worst-case run-time to end up performing well on…

Quantum Physics · Physics 2023-10-11 Chris Cade , Marten Folkertsma , Ido Niesen , Jordi Weggemans

Consider a Boolean function $\chi: X \to \{0,1\}$ that partitions set $X$ between its good and bad elements, where $x$ is good if $\chi(x)=1$ and bad otherwise. Consider also a quantum algorithm $\mathcal A$ such that $A |0\rangle=…

Quantum Physics · Physics 2021-03-23 Gilles Brassard , Peter Hoyer , Michele Mosca , Alain Tapp

Quantum computers can execute algorithms that dramatically outperform classical computation. As the best-known example, Shor discovered an efficient quantum algorithm for factoring integers, whereas factoring appears to be difficult for…

Quantum Physics · Physics 2010-01-19 Andrew M. Childs , Wim van Dam

Quantum amplitude amplification and estimation have shown quadratic speedups to unstructured search and estimation tasks. We show that a coherent combination of these quantum algorithms also provides a quadratic speedup to calculating the…

Quantum Physics · Physics 2024-12-03 Caleb Rotello

A quantum algorithm is a set of instructions for a quantum computer, however, unlike algorithms in classical computer science their results cannot be guaranteed. A quantum system can undergo two types of operation, measurement and quantum…

Data Structures and Algorithms · Computer Science 2007-05-30 Eva Borbely

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

We present a full implementation and simulation of a novel quantum reinforcement learning method. Our work is a detailed and formal proof of concept for how quantum algorithms can be used to solve reinforcement learning problems and shows…

Quantum Physics · Physics 2023-11-10 Simon Wiedemann , Daniel Hein , Steffen Udluft , Christian Mendl

Quantum Computing offers an entirely new way of doing computation governed by the rules of quantum mechanics like Superposition and Entanglement. These rules allow us to do computation over all the possible states simultaneously. Hence,…

Quantum Physics · Physics 2021-07-08 Mohd. Hussain Mir , Harkirat Singh

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

The use of superposition of states in quantum computation, known as quantum parallelism, has significant advantage in terms of speed over the classical computation. It can be understood from the early invented quantum algorithms such as…

Quantum Physics · Physics 2017-11-17 Pulak Ranjan Giri , Vladimir E. Korepin