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Related papers: On the Role of Hadamard Gates in Quantum Circuits

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Quantum algorithms are conventionally formulated for implementation on a single system of qubits amenable to projective measurements. However, in expectation value quantum computation, such as nuclear magnetic resonance realizations, the…

Quantum Physics · Physics 2007-05-23 David Collins

In this paper we discuss the problem of performing elementary finite field arithmetic on a quantum computer. Of particular interest, is the controlled-multiplication operation, which is the only group-specific operation in Shor's algorithms…

Quantum Physics · Physics 2007-05-23 Stephane Beauregard , Gilles Brassard , Jose M. Fernandez

The progress in building quantum computers to execute quantum algorithms has recently been remarkable. Grover's search algorithm in a binary quantum system provides considerable speed-up over classical paradigm. Further, Grover's algorithm…

Quantum Physics · Physics 2022-08-24 Amit Saha , Ritajit Majumdar , Debasri Saha , Amlan Chakrabarti , Susmita Sur-Kolay

Quantum gates are the building blocks of quantum circuits, which in turn are the cornerstones of quantum information processing. In this work, we theoretically investigate a single-step implementation of both a universal two- (CNOT) and…

Quantum Physics · Physics 2024-07-01 Luiz O. R. Solak , Daniel Z. Rossatto , Celso J. Villas-Boas

The Clifford group plays a central role in quantum randomized benchmarking, quantum tomography, and error correction protocols. Here we study the structural properties of this group. We show that any Clifford operator can be uniquely…

Quantum Physics · Physics 2022-04-11 Sergey Bravyi , Dmitri Maslov

We present two techniques that can greatly reduce the number of gates required to realize an energy measurement, with application to ground state preparation in quantum simulations. The first technique realizes that to prepare the ground…

Quantum Physics · Physics 2018-08-28 David Poulin , Alexei Kitaev , Damian S. Steiger , Matthew B. Hastings , Matthias Troyer

We apply a hybrid evolutionary algorithm to minimize the depth of circuits in quantum computing. More specifically, we evaluate two different variants of the algorithm. In the first approach, we combine the evolutionary algorithm with an…

High-fidelity and robust quantum manipulation is the key for scalable quantum computation. Therefore, due to the intrinsic operational robustness, quantum manipulation induced by geometric phases is one of the promising candidates. However,…

Quantum Physics · Physics 2020-09-23 Tao Chen , Pu Shen , Zheng-Yuan Xue

Variational quantum algorithms dominate contemporary gate-based quantum enhanced optimisation, eigenvalue estimation and machine learning. Here we establish the quantum computational universality of variational quantum computation by…

Quantum Physics · Physics 2021-05-25 Jacob Biamonte

Lately, much attention has been given to quantum algorithms that solve pattern recognition tasks in machine learning. Many of these quantum machine learning algorithms try to implement classical models on large-scale universal quantum…

Quantum Physics · Physics 2018-01-17 Maria Schuld , Mark Fingerhuth , Francesco Petruccione

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

The standard circuit model for quantum computation presumes the ability to directly perform gates between arbitrary pairs of qubits, which is unlikely to be practical for large-scale experiments. Power-law interactions with strength…

In an ordinary quantum algorithm the gates are applied in a fixed order on the systems. The introduction of indefinite causal structures allows to relax this constraint and control the order of the gates with an additional quantum state. It…

Quantum Physics · Physics 2022-06-15 Martin J. Renner , Časlav Brukner

We report the characterization of a universal set of logic gates for one-way quantum computing using a four-photon `star' cluster state generated by fusing photons from two independent photonic crystal fibre sources. We obtain a fidelity…

Quantum Physics · Physics 2013-12-25 B. A. Bell , M. S. Tame , A. S. Clark , R. W. Nock , W. J. Wadsworth , J. G. Rarity

Quantum computing employs controllable interactions to perform sequences of logical gates and entire algorithms on quantum registers. This paradigm has been widely explored, e.g., for simulating dynamics of manybody systems by decomposing…

Quantum Physics · Physics 2025-05-21 S. Alipour , A. T. Rezakhani , Alireza Tavanfar , K. Mölmer , T. Ala-Nissila

Gradient-based optimization is a key ingredient of variational quantum algorithms, with applications ranging from quantum machine learning to quantum chemistry and simulation. The parameter-shift rule provides a hardware-friendly method for…

Quantum Physics · Physics 2025-10-08 Leonardo Banchi , Dominic Branford , Chetan Waghela

The effect of unitary noise on the performance of Grover's quantum search algorithm is studied. This type of noise may result from tiny fluctuations and drift in the parameters of the (quantum) components performing the computation. The…

Quantum Physics · Physics 2009-11-10 D. Shapira , S. Mozes , O. Biham

The advent of quantum computing processors with possibility to scale beyond experimental capacities magnifies the importance of studying their applications. Combinatorial optimization problems can be one of the promising applications of…

Quantum Physics · Physics 2017-08-18 Ehsan Zahedinejad , Arman Zaribafiyan

We develop and implement automated methods for optimizing quantum circuits of the size and type expected in quantum computations that outperform classical computers. We show how to handle continuous gate parameters and report a collection…

Quantum Physics · Physics 2018-06-04 Yunseong Nam , Neil J. Ross , Yuan Su , Andrew M. Childs , Dmitri Maslov

Quantum circuits currently constitute a dominant model for quantum computation. Our work addresses the problem of constructing quantum circuits to implement an arbitrary given quantum computation, in the special case of two qubits. We…

Quantum Physics · Physics 2009-11-07 Stephen S. Bullock , Igor L. Markov