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Related papers: A Quantum Hamiltonian Identification Algorithm: Co…

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Quantum state tomography is a core task in quantum system identification. Real experimental conditions often deviate from nominal designs, introducing errors in both the measurement devices and the Hamiltonian governing the system's…

Quantum Physics · Physics 2025-12-16 Alan Chen , Shuixin Xiao , Hailan Ma , Daoyi Dong

Time-dependent Hamiltonian simulation (TDHS) is a critical task in quantum computing. Existing algorithms are generally biased with a small algorithmic error $\varepsilon$, and the gate complexity scales as $O(\text{poly}(1/\varepsilon))$…

Quantum Physics · Physics 2022-12-20 Xiao-Ming Zhang , Zixuan Huo , Kecheng Liu , Ying Li , Xiao Yuan

Quantum process tomography (QPT) methods aim at identifying a given quantum process. The present paper focuses on the estimation of a unitary process. This class is of particular interest because quantum mechanics postulates that the…

Quantum Physics · Physics 2024-01-23 François Verdeil , Yannick Deville

Simulating the unitary dynamics of a quantum system is a fundamental problem of quantum mechanics, in which quantum computers are believed to have significant advantage over their classical counterparts. One prominent such instance is the…

Quantum Physics · Physics 2024-09-04 John M. Martyn , Yuan Liu , Zachary E. Chin , Isaac L. Chuang

Holonomic quantum computation exploits a quantum state's non-trivial, matrix-valued geometric phase (holonomy) to perform fault-tolerant computation. Holonomies arising from systems where the Hamiltonian traces a continuous path through…

Quantum Physics · Physics 2022-02-08 Cornelis J. G. Mommers , Erik Sjöqvist

Various Hamiltonian simulation algorithms have been proposed to efficiently study the dynamics of quantum systems on a quantum computer. The existing algorithms generally approximate the time evolution operators, which may need a deep…

Quantum Physics · Physics 2024-03-14 Zi-Jian Zhang , Jinzhao Sun , Xiao Yuan , Man-Hong Yung

Quantum algorithms for probing ground-state properties of quantum systems require good initial states. Projection-based methods such as eigenvalue filtering rely on inputs that have a significant overlap with the low-energy subspace, which…

Quantum Physics · Physics 2024-04-10 Danial Motlagh , Modjtaba Shokrian Zini , Juan Miguel Arrazola , Nathan Wiebe

We present an empirical strategy to determine the Hamiltonian dynamics of a two-qubit system using only initialization and measurement in a single fixed basis. Signal parameters are estimated from measurement data using Bayesian methods…

Quantum Physics · Physics 2009-10-01 S. G. Schirmer , D. K. L. Oi

Characterizing quantum systems is a fundamental task that enables the development of quantum technologies. Various approaches, ranging from full tomography to instances of classical shadows, have been proposed to this end. However, quantum…

Quantum Physics · Physics 2025-06-16 Franz J. Schreiber , Jens Eisert , Johannes Jakob Meyer

We present a stochastic quantum computing algorithm that can prepare any eigenvector of a quantum Hamiltonian within a selected energy interval $[E-\epsilon, E+\epsilon]$. In order to reduce the spectral weight of all other eigenvectors by…

Quantum Physics · Physics 2021-07-26 Kenneth Choi , Dean Lee , Joey Bonitati , Zhengrong Qian , Jacob Watkins

The temporal evolution of a quantum system can be characterized by quantum process tomography, a complex task that consumes a number of physical resources scaling exponentially with the number of subsystems. An alternative approach to the…

Quantum signal processing provides an optimal procedure for simulating Hamiltonian evolution on a quantum computer using calls to a block encoding of the Hamiltonian. In many situations it is possible to control between forward and reverse…

Quantum Physics · Physics 2024-07-17 Dominic W. Berry , Danial Motlagh , Giacomo Pantaleoni , Nathan Wiebe

Time symmetry in quantum mechanics, where the current quantum state is determined jointly by both the past and the future, offers a more comprehensive description of physical phenomena. This symmetry facilitates both forward and backward…

Quantum Physics · Physics 2025-06-13 Shijie Wei , Jingwei Wen , Xiaogang Li , Peijie Chang , Bozhi Wang , Franco Nori , Guilu Long

An adiabatic quantum algorithm is essentially given by three elements: An initial Hamiltonian with known ground state, a problem Hamiltonian whose ground state corresponds to the solution of the given problem and an evolution schedule such…

Quantum Physics · Physics 2019-09-17 Davide Pastorello , Enrico Blanzieri

In this article, a novel fast randomized subspace system identification method for estimating combined deterministic-stochastic LTI state-space models, is proposed. The algorithm is especially well-suited to identify high-order and…

Systems and Control · Electrical Eng. & Systems 2023-12-12 Vatsal Kedia , Debraj Chakraborty

A quantum computer directly manipulates information stored in the state of quantum mechanical systems. The available operations have many attractive features but also underly severe restrictions, which complicate the design of quantum…

Quantum Physics · Physics 2015-06-26 Sos S. Agaian , Andreas Klappenecker

Computed tomography (CT) is an important imaging technique used in medical analysis of the internal structure of the human body. Previously, image segmentation methods were required after acquiring reconstructed CT images to obtain…

Quantum Physics · Physics 2024-09-17 Kyungtaek Jun

Quantum computing holds promise for revolutionizing computational chemistry simulations, particularly in drug discovery. However, current quantum hardware is limited by noise and scale, necessitating bridging technologies. This study…

Quantum Physics · Physics 2025-04-16 Marek Kowalik , Ellen Michael , Peter Pogány , Phalgun Lolur

Hamiltonian encoding is a methodology for revealing the mechanism behind the dynamics governing controlled quantum systems. In this paper, following Mitra and Rabitz [Phys. Rev. A 67, 033407 (2003)], we define mechanism via pathways of…

Quantum Physics · Physics 2025-02-20 Erez Abrams , Michael Kasprzak , Gaurav Bhole , Tak-San Ho , Herschel Rabitz

The system identification problem is to estimate dynamical parameters from the output data, obtained by performing measurements on the output fields. We investigate system identification for quantum linear systems. Our main objectives are…

Quantum Physics · Physics 2017-12-25 Matthew Levitt , Mădălin Guţă , Theodore Kypraios