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Related papers: Iterative Quantum Amplitude Estimation

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Quantum algorithms have been widely studied in the context of combinatorial optimization problems. While this endeavor can often analytically and practically achieve quadratic speedups, theoretical and numeric studies remain limited,…

Quantum Physics · Physics 2023-11-07 Lucas T. Brady , Stuart Hadfield

Despite much recent work, the true promise and limitations of the Quantum Alternating Operator Ansatz (QAOA) are unclear. A critical question regarding QAOA is to what extent its performance scales with the input size of the problem…

Quantum Physics · Physics 2023-12-07 John Golden , Andreas Bärtschi , Stephan Eidenbenz , Daniel O'Malley

Many quantum algorithms rely on the measurement of complex quantum amplitudes. Standard approaches to obtain the phase information, such as the Hadamard test, give rise to large overheads due to the need for global controlled-unitary…

Quantum Physics · Physics 2024-05-29 Yilun Yang , Arthur Christianen , Mari Carmen Bañuls , Dominik S. Wild , J. Ignacio Cirac

Quantum phase estimation (QPE) is a key quantum algorithm, which has been widely studied as a method to perform chemistry and solid-state calculations on future fault-tolerant quantum computers. Recently, several authors have proposed…

Quantum Physics · Physics 2024-02-05 Nick S. Blunt , Laura Caune , Róbert Izsák , Earl T. Campbell , Nicole Holzmann

We numerically investigate quantum circuit elementary-gate level instantiations of the standard Quantum Phase Estimation (QPE) algorithm for the task of computing the ground-state energy of a quantum magnet; the disordered fully-connected…

Quantum Physics · Physics 2026-03-02 Elijah Pelofske , Stephan Eidenbenz

Accurate calibration of control parameters in quantum gates is crucial for high-fidelity operations, yet it represents a significant time and resource challenge, necessitating periods of downtime for quantum computers. Robust Phase…

Quantum Physics · Physics 2024-07-29 Travis Hurant , Ke Sun , Zhubing Jia , Jungsang Kim , Kenneth R. Brown

The Phase Estimation Algorithm (PEA) is an important quantum algorithm used independently or as a key subroutine in other quantum algorithms. Currently most implementations of the PEA are based on qubits, where the computational units in…

Estimating correctly the quantum phase of a physical system is a central problem in quantum parameter estimation theory due to its wide range of applications from quantum metrology to cryptography. Ideally, the optimal quantum estimator is…

Quantum Physics · Physics 2021-06-09 Marco A. Rodríguez-García , Isaac Pérez Castillo , P. Barberis-Blostein

Two-stage stochastic programming is a problem formulation for decision-making under uncertainty. In the first stage, the actor makes a best "here and now" decision in the presence of uncertain quantities that will be resolved in the future,…

Grover's quantum search algorithm provides a quadratic speedup over the classical one. The computational complexity is based on the number of queries to the oracle. However, depth is a more modern metric for noisy intermediate-scale quantum…

Quantum Physics · Physics 2020-03-31 Kun Zhang , Vladimir E. Korepin

Quantum imaginary time evolution (QITE) is a recently proposed quantum-classical hybrid algorithm that is guaranteed to reach the lowest state of system. In this study, we present several improvements on QITE, mainly focusing on molecular…

Quantum Physics · Physics 2023-10-02 Takashi Tsuchimochi , Yoohee Ryo , Seiichiro L. Ten-no

Standard quantum amplitude estimation algorithms provide quadratic speedup to Monte-Carlo simulations but require a circuit depth that scales as inverse of the estimation error. In view of the shallow depth in near-term devices, the…

Quantum Physics · Physics 2024-10-03 Dinh-Long Vu , Bin Cheng , Patrick Rebentrost

Suppose $\boldsymbol{y}$ is a real random variable, and one is given access to ``the code'' that generates it (for example, a randomized or quantum circuit whose output is $\boldsymbol{y}$). We give a quantum procedure that runs the code…

Quantum Physics · Physics 2022-08-17 Robin Kothari , Ryan O'Donnell

Quantum computers are capable of calculating the energy gap of two electronic states by using the quantum phase difference estimation (QPDE) algorithm. The Bayesian inference based implementations for the QPDE have been reported so far, but…

Quantum Physics · Physics 2023-11-30 Kenji Sugisaki

The rapid development of noisy intermediate-scale quantum (NISQ) devices has raised the question of whether or not these devices will find commercial use. Unfortunately, a major shortcoming of many proposed NISQ-amenable algorithms, such as…

Quantum Physics · Physics 2021-10-22 Amara Katabarwa , Alex Kunitsa , Borja Peropadre , Peter Johnson

Quantum phase estimation~(QPE) is central to numerous quantum algorithms, yet its standard implementation demands an $\calO(m^{2})$-gate quantum Fourier transform~(QFT) on $m$ control qubits-a prohibitive overhead on near-term noisy…

Quantum Physics · Physics 2026-04-08 Akoramurthy B , Surendiran. B

Quantum machine learning (QML) has emerged as an innovative framework with the potential to uncover complex patterns by leveraging quantum systems ability to simulate and exploit high-dimensional latent spaces, particularly in learning…

Quantum Physics · Physics 2025-04-08 Ziqing Guo , Alex Khan , Victor S. Sheng , Shabnam Jabeen , Ziwen Pan

This paper is concerned with the phase estimation algorithm in quantum computing algorithms, especially the scenarios where (1) the input vector is not an eigenvector; (2) the unitary operator is not exactly implemented; (3) random…

Quantum Physics · Physics 2022-08-10 Xiantao Li

Quantum optimization algorithms offer a promising route to finding the ground states of target Hamiltonians on near-term quantum devices. None the less, it remains necessary to limit the evolution time and circuit depth as much as possible,…

Quantum Physics · Physics 2022-11-01 Chenfeng Cao , Yunlong Yu , Zipeng Wu , Nic Shannon , Bei Zeng , Robert Joynt

Recently, several deep learning methods are proposed for the gravitational wave data analysis. One is conditional variational auto encoder (CVAE), proposed by Gabbard et al. [1]. We study the accuracy of a CVAE in the context of the…

General Relativity and Quantum Cosmology · Physics 2020-02-28 Takahiro S. Yamamoto , Takahiro Tanaka