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Related papers: Precision bounds in noisy quantum metrology

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We suppose that a structure working as a quantum switch will be a significant element of future networks realizing transmissions of quantum information. In this chapter we analyze a process of switch's operating -- especially in systems…

Quantum Physics · Physics 2018-03-12 Marek Sawerwain , Joanna Wiśniewska

The qubit (or a system of two quantum dots) has become a standard paradigm for studying quantum information processes. Our focus is Decoherence due to interaction of the qubit with its environment, leading to noise. We consider quantum…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Ebad Kamil , Sushanta Dattagupta

Bosonic systems, particularly in quantum optics and atomic physics, are leading platforms for achieving quantum enhanced precision in parameter estimation. By exploiting properties such as mode and particle entanglement, it is possible to…

Quantum Physics · Physics 2026-02-19 Astghik Saharyan , Eloi Descamps , Arne Keller , Pérola Milman

This paper studies quantum limits to dynamical sensors in the presence of decoherence. A modified purification approach is used to obtain tighter quantum detection and estimation error bounds for optical phase sensing and optomechanical…

Quantum Physics · Physics 2013-07-04 Mankei Tsang

Quantum metrology protocols are typically designed around the assumption that we have an abundance of measurement data, but recent practical applications are increasingly driving interest in cases with very limited data. In this regime the…

Quantum Physics · Physics 2019-04-18 Jesús Rubio , Jacob Dunningham

In the current quantum computing paradigm, significant focus is placed on the reduction or mitigation of quantum decoherence. When designing new quantum processing units, the general objective is to reduce the amount of noise qubits are…

Quantum Physics · Physics 2026-02-17 Viacheslav Kuzmin , Wilfrid Somogyi , Ekaterina Pankovets , Alexey Melnikov

Quantum systems can be exploited for disruptive technologies but in practice quantum features are fragile due to noisy environments. Quantum coherence, a fundamental such feature, is a basis-dependent property that is known to exhibit a…

Designing encoding and decoding circuits to reliably send messages over many uses of a noisy channel is a central problem in communication theory. When studying the optimal transmission rates achievable with asymptotically vanishing error…

Quantum Physics · Physics 2024-11-07 Matthias Christandl , Alexander Müller-Hermes

A pivotal task in quantum metrology, and quantum parameter estimation in general, is to de- sign schemes that achieve the highest precision with given resources. Standard models of quantum metrology usually assume the dynamics is fixed, the…

Quantum Physics · Physics 2017-07-18 Jing Liu , Haidong Yuan

Quantum-enhanced measurements use highly non-classical quantum states in order to enhance the precision of the measurement of classical quantities, like the length of an optical cavity. The major goal is to beat the standard quantum limit…

Quantum Physics · Physics 2009-05-29 Daniel Braun , John Martin

The major problem of multiparameter quantum estimation theory is to find an ultimate measurement scheme to go beyond the standard quantum limits that each quasi-classical estimation measurement is limited by. Although, in some specifics…

Quantum Physics · Physics 2022-03-21 Bakmou Lahcen , Daoud Mohammed

The external control circuits of quantum gates inevitably introduce a small but finite noise to the operation of quantum computers. The complex modes of decoherence introduced by this noise are not covered by the common error models. Using…

Quantum Physics · Physics 2007-05-23 Jürgen T. Stockburger

Quantum-dense metrology (QDM) constitutes a special case of quantum metrology in which two orthogonal phase space projections of a signal are simultaneously sensed beyond the shot noise limit. Previously it was shown that the additional…

Quantum Physics · Physics 2016-11-02 Melanie Ast , Sebastian Steinlechner , Roman Schnabel

We investigate the advantage of coherent superposition of two different coded channels in quantum metrology. In a continuous variable system, we show that the Heisenberg limit $1/N$ can be beaten by the coherent superposition without the…

Quantum Physics · Physics 2021-12-15 Dong Xie , Chunling Xu , An Min Wang

Quantum error detection can produce unbiased expectation values that exponentially converge to noiseless results as the code distance is increased. Despite this, its performance as an error mitigation technique is relatively understudied on…

Quantum Physics · Physics 2026-05-05 Yanis Le Fur , Ethan Egger , Hong-Ye Hu , Vincent Russo , William J. Zeng , Ryan LaRose

Quantum decoherence arises due to uncontrollable entanglement between a system with its environment. However the effects of decoherence are often thought of and modeled through a simpler picture in which the role of the environment is to…

Quantum Physics · Physics 2019-09-17 Bing Gu , Ignacio Franco

We derive fundamental bounds for general quantum metrological models involving both temporal or spatial correlations (mathematically described by quantum combs), which may be effectively computed in the limit of a large number of probes or…

Quantum Physics · Physics 2025-09-24 Stanislaw Kurdzialek , Francesco Albarelli , Rafal Demkowicz-Dobrzanski

Quantum metrology overcomes standard precision limits by exploiting collective quantum superpositions of physical systems used for sensing, with the prominent example of non-classical multiphoton states improving interferometric techniques.…

In this paper, we propose a scheme to eliminate the influence of noises on system dynamics, by means of a sequential unsharp measurements and unitary feedback operations. The unsharp measurements are carried out periodically during system…

Quantum Physics · Physics 2018-09-19 Du Ran , Ye-Hong Chen , Zhi-Cheng Shi , Zhen-Biao Yang , Jie Song , Yan Xia

We consider frequency estimation in a noisy environment with noisy probes. This builds on previous studies, most of which assume that the initial probe state is pure, while the encoding process is noisy, or that the initial probe state is…