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Related papers: Quantum Hamiltonian Learning for the Fermi-Hubbard…

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Quantum metrology leverages quantum resources such as entanglement and squeezing to enhance parameter estimation precision beyond classical limits. While optimal quantum control strategies can assist to reach or even surpass the Heisenberg…

Quantum Physics · Physics 2025-10-17 Qifei Wei , Shengshi Pang

The fermionic Hubbard model (FHM)[1], despite its simple form, captures essential features of strongly correlated electron physics. Ultracold fermions in optical lattices[2, 3] provide a clean and well-controlled platform for simulating…

Characterizing the Hamiltonians of continuous-variable (CV) quantum systems is a fundamental challenge laden with difficulties arising from infinite-dimensional Hilbert spaces and unbounded operators. Existing protocols for achieving the…

Quantum Physics · Physics 2025-10-10 Xi Huang , Lixing Zhang , Di Luo

The physics of a closed quantum mechanical system is governed by its Hamiltonian. However, in most practical situations, this Hamiltonian is not precisely known, and ultimately all there is are data obtained from measurements on the system.…

It is not possible, using standard lattice techniques in Euclidean space, to calculate the complete fermionic spectrum of a quantum field theory. Algorithms running on quantum computers have the potential to access the theory with real-time…

High Energy Physics - Lattice · Physics 2021-09-27 Giovanni Pederiva , Alexei Bazavov , Brandon Henke , Leon Hostetler , Dean Lee , Huey-Wen Lin , Andrea Shindler

Identifying an accurate model for the dynamics of a quantum system is a vexing problem that underlies a range of problems in experimental physics and quantum information theory. Recently, a method called quantum Hamiltonian learning has…

Quantum Physics · Physics 2014-04-23 Nathan Wiebe , Christopher Granade , Christopher Ferrie , David G. Cory

The utility of solving the Fermi-Hubbard model has been estimated in the billions of dollars. Digital quantum computers can in principle address this task, but have so far been limited to quasi one-dimensional models. This is because of…

We formalize and study the Hamiltonian certification problem. Given access to $e^{-\mathrm{i} Ht}$ for an unknown Hamiltonian $H$, the goal of the problem is to determine whether $H$ is $\varepsilon_1$-close to or $\varepsilon_2$-far from a…

Quantum Physics · Physics 2026-05-07 Minbo Gao , Zhengfeng Ji , Qisheng Wang , Wenjun Yu , Qi Zhao

Large-scale quantum devices provide insights beyond the reach of classical simulations. However, for a reliable and verifiable quantum simulation, the building blocks of the quantum device require exquisite benchmarking. This benchmarking…

Quantum Physics · Physics 2022-02-16 Agnes Valenti , Guliuxin Jin , Julian Léonard , Sebastian D. Huber , Eliska Greplova

In the accompanying paper of arXiv:2505.00697, we have presented a generalized scheme of adaptive quantum gradient estimation (QGE) algorithm, and further proposed two practical variants which not only achieve doubly quantum enhancement in…

Quantum Physics · Physics 2025-05-05 Yuki Koizumi , Kaito Wada , Wataru Mizukami , Nobuyuki Yoshioka

We propose a measurement setup reaching Heisenberg scaling precision for the estimation of any distributed parameter $\varphi$ (not necessarily a phase) encoded into a generic $M$-port linear network composed only of passive elements. The…

Quantum Physics · Physics 2021-12-23 Giovanni Gramegna , Danilo Triggiani , Paolo Facchi , Frank A. Narducci , Vincenzo Tamma

As the size of quantum devices continues to grow, the development of scalable methods to characterise and diagnose noise is becoming an increasingly important problem. Recent methods have shown how to efficiently estimate Hamiltonians in…

Quantum Physics · Physics 2019-12-18 Tim J. Evans , Robin Harper , Steven T. Flammia

The Heisenberg scaling is an ultimate precision limit of parameter estimation allowed by the principles of quantum mechanics, with no counterpart in the classical realm, and has been a long-pursued goal in quantum metrology. It has been…

Quantum Physics · Physics 2024-12-06 Jingyi Fan , Shengshi Pang

We address the issue of precisely estimating small parameters encoded in a general linear transformation of the modes of a bosonic quantum field. Such Bogoliubov transformations frequently appear in the context of quantum optics. We provide…

Quantum Physics · Physics 2015-08-10 Nicolai Friis , Michalis Skotiniotis , Ivette Fuentes , Wolfgang Dür

We give an improved algorithm for learning a quantum Hamiltonian given copies of its Gibbs state, that can succeed at any temperature. Specifically, we improve over the work of Bakshi, Liu, Moitra, and Tang [BLMT24], by reducing the sample…

Quantum Physics · Physics 2024-07-08 Shyam Narayanan

Quantum phase estimation is a cornerstone in quantum algorithm design, allowing for the inference of eigenvalues of exponentially-large sparse matrices.The maximum rate at which these eigenvalues may be learned, --known as the Heisenberg…

Quantum Physics · Physics 2022-10-12 Alicja Dutkiewicz , Barbara M. Terhal , Thomas E. O'Brien

Estimating parameters of quantum systems is usually done by performing a sequence of predetermined experiments and post-processing the resulting data. It is known that online design, where the choice of the next experiment is based on the…

Quantum Physics · Physics 2018-06-08 Ian Hincks , Thomas Alexander , Michal Kononenko , Benjamin Soloway , David G. Cory

Quantum generative learning is a promising application of quantum computers, but faces several trainability challenges, including the difficulty in experimental gradient estimations. For certain structured quantum generative models,…

Quantum Physics · Physics 2025-11-19 Bence Bakó , Zoltán Kolarovszki , Zoltán Zimborás

The rapid progress in quantum computing (QC) and machine learning (ML) has attracted growing attention, prompting extensive research into quantum machine learning (QML) algorithms to solve diverse and complex problems. Designing…

Quantum Physics · Physics 2025-01-13 Samuel Yen-Chi Chen , Huan-Hsin Tseng , Hsin-Yi Lin , Shinjae Yoo

Quantum computation can be achieved by preparing an appropriate initial product state of qudits and then letting it evolve under a fixed Hamiltonian. The readout is made by measurement on individual qudits at some later time. This approach…

Quantum Physics · Physics 2015-12-22 Tzu-Chieh Wei , John C. Liang