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Related papers: Explaining Robust Quantum Metrology by Counting Co…

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Interactions among sensors can provide, in addition to entanglement, an important resource for boosting the precision in quantum estimation protocols. Dephasing noise, however, remains a leading source of decoherence in state-of-the-art…

Quantum Physics · Physics 2025-01-03 Francisco Riberi , Lorenza Viola

Quantum correlations can be harnessed to improve the precision in parameter estimation beyond classical capabilities. Under a standard interferometric or rotation protocol, it is well established that the optimal single-mode Gaussian state…

Quantum Physics · Physics 2026-04-14 Rubén Gordillo-Hachuel , Erik Torrontegui , Cristina de Dios , Ricardo Puebla

Entanglement is an important quantum resource to achieve high sensitive quantum metrology. However, the rapid decoherence of quantum entangled states, due to the unavoidable environment noise, result in practically the unwanted sharp drop…

Quantum Physics · Physics 2023-06-21 X. N. Feng , D. He , L. F. Wei

In this paper we develop two axiomatic tests for the controllability of subsystem codes embedded in decoherence-free subspaces of open quantum systems. The tests expand on existing control theory by considering quantum subsystems where a…

Quantum Physics · Physics 2025-03-10 Eric B. Kopp , Raymond Kwong

It is a major goal in quantum thermometry to reach a $1/N$ scaling of thermometric precision known as Heisenberg scaling but is still in its infancy to date. The main obstacle is that the resources typically required are highly entangled…

Quantum Physics · Physics 2022-07-11 Da-Jian Zhang , D. M. Tong

Quantum error correction codes (QECCs) play a central role in both quantum communications and quantum computation. Practical quantum error correction codes, such as stabilizer codes, are generally structured to suit a specific use, and…

Quantum Physics · Physics 2023-10-30 Diogo Cruz , Francisco A. Monteiro , Bruno C. Coutinho

Quantum error correction is essential for reliable quantum computation, where surface codes demonstrate high fault-tolerant thresholds and hardware efficiency. However, noise in single-shot measurements limits logical readout fidelity,…

Quantum Physics · Physics 2025-05-13 Xiao-Yue Xu , Chen Ding , Wan-Su Bao

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

Critical ground states of quantum many-body systems have emerged as vital resources for quantum-enhanced sensing. Traditional methods to prepare these states often rely on adiabatic evolution, which may diminish the quantum sensing…

Quantum Physics · Physics 2025-03-05 Hang Xu , Tailong Xiao , Jingzheng Huang , Ming He , Jianping Fan , Guihua Zeng

Non-Hermitian quantum metrology, an emerging field at the intersection of quantum estimation and non-Hermitian physics, holds promise for revolutionizing precision measurement. Here, we present a comprehensive investigation of non-Hermitian…

Quantum Physics · Physics 2025-09-17 Xinglei Yu , Xinzhi Zhao , Liangsheng Li , Xiao-Min Hu , Xiangmei Duan , Haidong Yuan , Chengjie Zhang

Quantum metrology explores quantum effects to improve the measurement accuracy of some physical quantities beyond the classical limit. However, due to the interaction between the system and the environment, the decoherence can significantly…

Quantum Physics · Physics 2024-05-07 Cheng-Ge Liu , Cong-Wei Lu , Na-Na Zhang , Qing Ai

Non-local observables play an important role in quantum theory, from Bell inequalities and various post-selection paradoxes to quantum error correction codes. Instantaneous measurement of these observables is known to be a difficult…

Quantum Physics · Physics 2016-02-22 Aharon Brodutch , Eliahu Cohen

Heisenberg scaling characterizes the ultimate precision of parameter estimation enabled by quantum mechanics, which represents an important quantum advantage of both theoretical and technological interest. Here, we study the attainability…

Quantum Physics · Physics 2022-04-26 Masahito Hayashi , Zi-Wen Liu , Haidong Yuan

Optical magnetometers use the rotation of linearly polarized laser light induced by the Faraday effect for high precision magnetic field measurements. Here, we carry out an in-depth quantum information investigation, deploying two distinct…

Quantum Physics · Physics 2026-01-06 Georg Engelhardt , Ming Li , Xingchang Wang , JunYan Luo , J. F. Chen

Quantum machine learning models have the potential to offer speedups and better predictive accuracy compared to their classical counterparts. However, these quantum algorithms, like their classical counterparts, have been shown to also be…

Quantum Physics · Physics 2021-05-27 Maurice Weber , Nana Liu , Bo Li , Ce Zhang , Zhikuan Zhao

Significant achievements in the reduction of classical-noise floor will allow macroscopic systems to prepare nearly Heisenberg-Limited quantum states through a continuous measurement, i.e. conditioning. In order to probe the conditional…

We study the problem of two superconducting quantum qubits coupled via a resonator. If only one quanta is present in the system and the number of photons in the resonator is measured with a null result, the qubits end up in an entangled…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jian Li , K. Chalapat , G. S. Paraoanu

Quantum metrology seeks to leverage the richness of quantum systems for making better measurements than are possible using only classical resources in order to gain a ``quantum advantage''. Quantum metrology schemes must also be resilient…

Many quantum information tasks rely on entanglement, which is used as a resource, for example, to enable efficient and secure communication. Typically, noise, accompanied by loss of entanglement, reduces the efficiency of quantum protocols.…

Identifying quantum resources for quantum sensing is of paramount importance. Up to date, two quantum resources has been widely recognized: the number $N$ of entangled quantum probes and the coherent evolution time $T$. Here we identify the…

Quantum Physics · Physics 2024-05-28 Qi Chai , Wen Yang