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Related papers: Closed-Form Optimal Quantum Circuits for Single-Qu…

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The accurate identification of faulty hardware is a fundamental requirement for reliable quantum information processing. We address this problem in a quantum setting, where a series of $n$ devices is intended to apply the same unitary…

Quantum Physics · Physics 2026-05-07 Santiago Llorens , Arnau Diebra , Michal Sedlák , Ramon Muñoz-Tapia

Quantum fidelity is a measure to quantify the closeness of two quantum states. In an operational sense, it is defined as the minimal overlap between the probability distributions of measurement outcomes and the minimum is taken over all…

Quantum Physics · Physics 2019-07-24 Changhun Oh , Changhyoup Lee , Leonardo Banchi , Su-Yong Lee , Carsten Rockstuhl , Hyunseok Jeong

Quantum algorithms can be analyzed in a query model to compute Boolean functions where input is given in a black box, but the aim is to compute function value for arbitrary input using as few queries as possible. In this paper we…

Quantum Physics · Physics 2012-03-24 Alina Dubrovska Vasilieva , Taisia Mischenko-Slatenkova

In the standard oracle model, an oracle efficiently evaluates an unknown classical function independent of the quantum algorithm itself. Quantum algorithms have a complex interrelationship to their oracles; for example the possibility of…

Quantum Physics · Physics 2022-06-29 Cica Gustiani , David P. DiVincenzo

Given an arbitrary single-qubit operation, an important task is to efficiently decompose this operation into an (exact or approximate) sequence of fault-tolerant quantum operations. We derive a depth-optimal canonical form for single-qubit…

Quantum Physics · Physics 2012-12-13 Alex Bocharov , Krysta M. Svore

We present a classically solvable model that leads to optimized low-depth quantum circuits leveraging separable pair approximations. The obtained circuits are well suited as a baseline circuit for emerging quantum hardware and can, in the…

Quantum Physics · Physics 2022-04-07 Jakob S. Kottmann , Alán Aspuru-Guzik

The conventional paradigm of quantum computing is discrete: it utilizes discrete sets of gates to realize bitstring-to-bitstring mappings, some of them arguably intractable for classical computers. In parameterized quantum approaches, the…

Quantum Physics · Physics 2025-12-12 Adrián Pérez-Salinas , Mahtab Yaghubi Rad , Alice Barthe , Vedran Dunjko

We present several families of total boolean functions which have exact quantum query complexity which is a constant multiple (between 1/2 and 2/3) of their classical query complexity, and show that optimal quantum algorithms for these…

Quantum Physics · Physics 2016-02-24 Ashley Montanaro , Richard Jozsa , Graeme Mitchison

This paper considers the quantum query complexity of {\it $\eps$-biased oracles} that return the correct value with probability only $1/2 + \eps$. In particular, we show a quantum algorithm to compute $N$-bit OR functions with…

Quantum Physics · Physics 2007-05-23 Tomoya Suzuki , Shigeru Yamashita , Masaki Nakanishi , Katsumasa Watanabe

Quantum entanglement is a unique criterion of the quantum realm and an essential tool to secure quantum communication. Ensuring high-fidelity entanglement has always been a challenging task owing to interaction with the hostile channel…

Quantum Physics · Physics 2025-07-23 Syed Emad Uddin Shubha , Md. Saifur Rahman , M. R. C. Mahdy

We present a depth-aware optimization framework for quantum circuit compilation that unifies provable optimality with scalable heuristics. For exact synthesis of a target unitary, we formulate a mixed-integer linear program (MILP) that…

Quantum Physics · Physics 2025-10-02 Harsha Nagarajan , Zsolt Szabó

Here, we study the problem of decoding information transmitted through unknown quantum states. We assume that Alice encodes an alphabet into a set of orthogonal quantum states, which are then transmitted to Bob. However, the quantum channel…

Quantum Physics · Physics 2023-05-09 D. Concha , L. Pereira , L. Zambrano , A. Delgado

Given a function f as an oracle, the collision problem is to find two distinct inputs i and j such that f(i)=f(j), under the promise that such inputs exist. Since the security of many fundamental cryptographic primitives depends on the…

Quantum Physics · Physics 2011-11-04 Yaoyun Shi

Implementing many important sub-circuits on near-term quantum devices remains a challenge due to the high levels of noise and the prohibitive depth on standard nearest-neighbour topologies. Overcoming these barriers will likely require…

Quantum Physics · Physics 2024-11-06 Angus Mingare , Anastasia Moroz , Marcell D Kovacs , Andrew G Green

Quantum computations promise the ability to solve problems intractable in the classical setting. Restricting the types of computations considered often allows to establish a provable theoretical advantage by quantum computations, and later…

Quantum Physics · Physics 2021-11-19 Dmitri Maslov , Jin-Sung Kim , Sergey Bravyi , Theodore J. Yoder , Sarah Sheldon

The minimum error probability for distinguishing between two quantum states is bounded by the Helstrom limit, derived under the assumption that measurement strategies are restricted to positive operator-valued measurements. We explore…

Quantum Physics · Physics 2026-01-28 Swati Choudhary , Aparajita Bhattacharyya , Ujjwal Sen

This paper deals with the quantum optimal discrimination among mixed quantum states enjoying geometrical uniform symmetry with respect to a reference density operator $\rho_0$. It is well-known that the minimal error probability is given by…

Quantum Physics · Physics 2015-05-14 Antonio Assalini , Gianfranco Cariolaro , Gianfranco Pierobon

Random quantum circuits have played a central role in establishing the computational advantages of near-term quantum computers over their conventional counterparts. Here, we use ensembles of low-depth random circuits with local connectivity…

Quantum Physics · Physics 2021-09-29 Michael J. Gullans , Stefan Krastanov , David A. Huse , Liang Jiang , Steven T. Flammia

Among certification techniques, those based on the violation of Bell inequalities are appealing because they do not require assumptions on the underlying Hilbert space dimension and on the accuracy of calibration methods. Such…

Quantum Physics · Physics 2020-03-20 Sebastian Wagner , Jean-Daniel Bancal , Nicolas Sangouard , Pavel Sekatski

Quantum gates executed on physical hardware are inevitably degraded by environmental noise. While state purification effectively distills static quantum resources, the dynamic execution of quantum algorithms requires a higher-order approach…

Quantum Physics · Physics 2026-04-02 Jiayi Zhao , Yu-Ao Chen , Guocheng Zhen , Chengkai Zhu , Ranyiliu Chen , Xin Wang