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As a promising candidate for exhibiting quantum computational supremacy, Gaussian Boson Sampling (GBS) is designed to exploit the ease of experimental preparation of Gaussian states. However, sufficiently large and inevitable experimental…

Quantum Physics · Physics 2020-03-18 Haoyu Qi , Daniel J. Brod , Nicolás Quesada , Raúl García-Patrón

We present a novel approach for designing complex approximate arithmetic circuits that trade correctness for power consumption and play important role in many energy-aware applications. Our approach integrates in a unique way formal methods…

Neural and Evolutionary Computing · Computer Science 2020-07-03 Milan Ceska , Jiri Matyas , Vojtech Mrazek , Lukas Sekanina , Zdenek Vasicek , Tomas Vojnar

BosonSampling is a restricted model of quantum computation proposed recently, where a non-adaptive linear-optical network is used to solve a sampling problem that seems to be hard for classical computers. Here we show that, even if the…

Quantum Physics · Physics 2015-04-22 Daniel J. Brod

We present methods which allow orders of magnitude increase in the number of modes in linear optics experiments by moving from spatial encoding to temporal encoding and using dispersion. This enables significant practical advantages for…

Quantum Physics · Physics 2016-05-17 Mihir Pant , Dirk Englund

This paper extends the framework of randomised matrix multiplication to a coarser partition and proposes an algorithm as a complement to the classical algorithm, especially when the optimal probability distribution of the latter one is…

Numerical Analysis · Mathematics 2019-05-20 Yue Wu

Estimating properties of quantum states, such as fidelities, molecular energies, and correlation functions, is a fundamental task in quantum information science. Due to the limitation of practical quantum devices, including limited circuit…

Quantum Physics · Physics 2025-10-17 Bujiao Wu , Lingyu Kong , Yuxuan Yan , Fuchuan Wei , Zhenhuan Liu

We propose a method for constructing $\texttt{PREPARE}$ circuits for quantum phase estimation of a molecular Hamiltonian in quantum chemistry by using variational optimization of quantum circuits solely on classical computers. The…

Quantum Physics · Physics 2025-05-02 Hayata Morisaki , Kosuke Mitarai , Keisuke Fujii , Yuya O. Nakagawa

Unitary Fourier transform lies at the core of the multitudinous computational and metrological algorithms. Here we show experimentally how the unitary Fourier transform-based phase estimation protocol, used namely in quantum metrology, can…

One of the core research questions in the theory of quantum computing is to find out to what precise extent the classical simulation of a noisy quantum circuits is possible and where potential quantum advantages can set in. In this work, we…

Quantum Physics · Physics 2026-01-09 Janek Denzler , Jose Carrasco , Jens Eisert , Tommaso Guaita

We introduce a hybrid classical-quantum algorithm to compute dynamical correlation functions and excitation spectra in many-body quantum systems, with a focus on molecular systems. The method combines classical preparation of a perturbed…

Quantum Physics · Physics 2025-10-30 Alessandro Santini , Stefano Barison , Filippo Vicentini

In order to find the outcome probabilities of quantum mechanical systems like the optical networks underlying Boson sampling, it is necessary to be able to compute the permanents of unitary matrices, a computationally hard task. Here we…

Quantum Physics · Physics 2022-02-10 P. H. Lundow , K. Markström

Scientists in quantum technology aspire to quantum advantage: a computational result unattainable with classical computers. Gaussian boson sampling experiment has been already claimed to achieve this goal. In this setup squeezed light…

Quantum Physics · Physics 2022-07-08 A. S. Popova , A. N. Rubtsov

Variational quantum algorithms (VQAs) provide a promising approach to achieving quantum advantage for practical problems on near-term noisy intermediate-scale quantum (NISQ) devices. Thus far, most studies on VQAs have focused on…

Quantum Physics · Physics 2023-10-06 Yutaro Enomoto , Keitaro Anai , Kenta Udagawa , Shuntaro Takeda

Stochastic models are highly relevant tools in science, engineering, and society. Recent work suggests emerging quantum computing technologies can substantially decrease the memory requirements for simulating stochastic models. Here we show…

Quantum Physics · Physics 2019-06-04 John Realpe-Gómez , Nathan Killoran

A wide variety of imaging systems have been designed to measure phase variations, with applications from physics to biology and medicine. In this work, we theoretically compare the precision of phase estimations achievable with classical…

Optics · Physics 2021-05-21 Dorian Bouchet , Jonathan Dong , Dante Maestre , Thomas Juffmann

Quantum advantage, benchmarking the computational power of quantum machines outperforming all classical computers in a specific task, represents a crucial milestone in developing quantum computers and has been driving different physical…

We propose a variational scheme to represent composite quantum systems using multiple parameterized functions of varying accuracies on both classical and quantum hardware. The approach follows the variational principle over the entire…

Quantum Physics · Physics 2024-06-21 Stefano Barison , Filippo Vicentini , Giuseppe Carleo

Despite extensive research efforts, few quantum algorithms for classical optimization demonstrate realizable quantum advantage. The utility of many quantum algorithms is limited by high requisite circuit depth and nonconvex optimization…

Quantum Physics · Physics 2022-01-27 Taylor L. Patti , Jean Kossaifi , Anima Anandkumar , Susanne F. Yelin

We describe a quantum algorithm that solves combinatorial optimization problems by quantum simulation of a classical simulated annealing process. Our algorithm exploits quantum walks and the quantum Zeno effect induced by evolution…

Quantum Physics · Physics 2009-02-02 R. D. Somma , S. Boixo , H. Barnum , E. Knill

We consider the problem of developing automated techniques for solving recurrence relations to aid the expected-runtime analysis of programs. Several classical textbook algorithms have quite efficient expected-runtime complexity, whereas…

Programming Languages · Computer Science 2017-05-02 Krishnendu Chatterjee , Hongfei Fu , Aniket Murhekar