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Related papers: Process Tomography for Systems in a Thermal State

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The method of tempered transitions was proposed by Neal (1996) for tackling the difficulties arising when using Markov chain Monte Carlo to sample from multimodal distributions. In common with methods such as simulated tempering and…

Computation · Statistics 2012-09-11 Gundula Behrens , Nial Friel , Merrilee Hurn

We study the effects of preparation of input states in a quantum tomography experiment. We show that maps arising from a quantum process tomography experiment (called process maps) differ from the well know dynamical maps. The difference…

Quantum Physics · Physics 2009-10-29 Aik-meng Kuah , Kavan Modi , César A. Rodríguez-Rosario , E. C. G. Sudarshan

In medical research, understanding changes in outcome measurements is crucial for inferring shifts in health conditions. However, traditional methods often struggle with large, irregularly longitudinal data and fail to account for the…

Applications · Statistics 2025-03-13 Yu Luo , Chris Sherlock

A hidden Markov process is a well known concept in information theory and is used for a vast range of applications such as speech recognition and error correction. We bridge between two disciplines, experimental physics and advanced…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 Ido Kanter , Aviad Frydman , Asaf Ater

Optimizing open quantum system evolution is an important step on the way to achieving quantum computing and quantum thermodynamic tasks. In this article, we approach optimisation via variational principles and derive an open quantum system…

Quantum Physics · Physics 2018-10-17 Nishchay Suri , Felix C. Binder , Bhaskaran Muralidharan , Sai Vinjanampathy

Quantum process tomography is an experimental technique to fully characterize an unknown quantum process. Standard quantum process tomography suffers from exponentially scaling of the number of measurements with the increasing system size.…

Quantum Physics · Physics 2022-08-02 Shichuan Xue , Yong Liu , Yang Wang , Pingyu Zhu , Chu Guo , Junjie Wu

Established techniques for simulation and prediction with Gaussian process (GP) dynamics often implicitly make use of an independence assumption on successive function evaluations of the dynamics model. This can result in significant error…

Machine Learning · Computer Science 2020-05-05 Lukas Hewing , Elena Arcari , Lukas P. Fröhlich , Melanie N. Zeilinger

We present an algorithm that prepares thermal Gibbs states of one dimensional quantum systems on a quantum computer without any memory overhead, and in a time significantly shorter than other known alternatives. Specifically, the time…

Quantum Physics · Physics 2010-10-29 Ersen Bilgin , Sergio Boixo

In this work, we model the temperature measurement as a transformation of the arbitrary state into the Gibbs state. We start with a general formalism of ansatz-posteriors, which includes many usual models of posterior states due to…

Quantum Physics · Physics 2026-04-03 N. M. Gerasimov , A. E. Teretenkov

We study characteristics of superpositions and entanglement of thermal states at high temperatures and discuss their applications to quantum information processing. We introduce thermal-state qubits and thermal-Bell states, which are a…

Quantum Physics · Physics 2007-10-03 Hyunseok Jeong , Timothy C. Ralph

The impressive pace of advance of quantum technology calls for robust and scalable techniques for the characterization and validation of quantum hardware. Quantum process tomography, the reconstruction of an unknown quantum channel from…

Dirac-Frenkel variational method with Davydov D2 trial wavefunction is extended by introducing a thermalization algorithm and applied to simulate dynamics of a general open quantum system. The algorithm allows to control temperature…

Quantum Physics · Physics 2021-03-04 Mantas Jakučionis , Darius Abramavičius

We study the number of measurements required for quantum process tomography under prior information, such as a promise that the unknown channel is unitary. We introduce the notion of an interactive observable and we show that any unitary…

Quantum Physics · Physics 2014-03-31 Gus Gutoski , Nathaniel Johnston

As the method to completely characterize quantum dynamical processes, quantum process tomography (QPT) is vitally important for quantum information processing and quantum control, where the faithfulness of quantum devices plays an essential…

Quantum Physics · Physics 2013-09-24 Yu-Xiang Zhang , Shengjun Wu , Zeng-Bing Chen

At non-zero temperature classical systems exhibit statistical fluctuations of thermodynamic quantities arising from the variation of the system's initial conditions and its interaction with the environment. The fluctuating work, for…

Quantum Physics · Physics 2018-02-07 Rui Sampaio , Samu Suomela , Tapio Ala-Nissila , Janet Anders , Thomas Philbin

The concept of randomized measurements on individual particles has proven to be useful for analyzing quantum systems and is central for methods like shadow tomography of quantum states. We introduce $\textit{collective}$ randomized…

Quantum Physics · Physics 2024-08-12 Satoya Imai , Géza Tóth , Otfried Gühne

Most protocols for Quantum Information Processing consist of a series of quantum gates, which are applied sequentially. In contrast, interactions, for example between matter and fields, as well as measurements such as homodyne detection of…

Quantum Physics · Physics 2015-06-15 Christine A. Muschik , Klemens Hammerer , Eugene S. Polzik , Ignacio J. Cirac

Recent years have seen a huge development in spatial modelling and prediction methodology, driven by the increased availability of remote-sensing data and the reduced cost of distributed-processing technology. It is well known that…

Computation · Statistics 2020-02-18 Andrew Zammit-Mangion , Jonathan Rougier

We propose an iterative proposal to estimate critical points for statistical models based on configurations by combing machine-learning tools. Firstly, phase scenarios and preliminary boundaries of phases are obtained by…

Disordered Systems and Neural Networks · Physics 2019-10-23 X. L. Zhao , L. B. Fu

We present a general protocol for estimating $M$ observables from only $\mathcal{O}(\log (M)/\varepsilon^2)$ copies of a Gibbs state whose Hamiltonian is accessible. The protocol uses single-copy, nonadaptive measurements and uses a total…

Quantum Physics · Physics 2026-03-18 Chi-Fang Chen , András Gilyén