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Related papers: Phase-Driven Precision Boost in Quantum Compressio…

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In the scenario of the probe-ancilla interaction, we propose a quantum metrology protocol by the unconditional measurement on the ancillary qubit after an optimized period of joint evolution from product state. Its key element is the…

Quantum Physics · Physics 2025-09-12 Peng Chen , Jun Jing

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

Quantum cryptographic conferencing (QCC) allows multiple parties to establish common secure keys in quantum networks with information-theoretic security. However, the secure transmission distances of current QCC implementations are still…

Quantum Physics · Physics 2026-01-27 Mi Zou , Bin-Chen Li , Shuai Zhao , Yingqiu Mao , Dandan Qin , Xiao Jiang , Teng-Yun Chen , Jian-Wei Pan

Measurement noise is a major source of noise in quantum metrology. Here, we explore preprocessing protocols that apply quantum controls to the quantum sensor state prior to the final noisy measurement (but after the unknown parameter has…

Quantum Physics · Physics 2023-12-11 Sisi Zhou , Spyridon Michalakis , Tuvia Gefen

Quantum metrology overcomes standard precision limits and plays a central role in science and technology. Practically it is vulnerable to imperfections such as decoherence. Here, we demonstrate quantum metrology for noisy channels such that…

Quantum Physics · Physics 2018-04-25 Kunkun Wang , Xiaoping Wang , Xiang Zhan , Zhihao Bian , Jian Li , Barry C. Sanders , Peng Xue

Biphoton frequency comb (BFC), which encompasses multiple discrete frequency modes and represents high-dimensional frequency entanglement, is crucial in quantum information processing due to its high information capacity and error…

Quantum Physics · Physics 2025-07-30 Baihong Li , Qi-qi Li , Boxin Yuan , Ruifang Dong , Shougang Zhang , Rui-Bo Jin

We propose an approach to measure the quantum phase of an electron in a non-Abelian system using the algorithm of Quantum Phase Estimation (QPE). The discrete-path systems were previously studied in the context of square or rectangular…

Quantum Physics · Physics 2025-09-15 Seng Ghee Tan , Son-Hsien Chen , Ying-Cheng Yang , Yen-Fu Chen , Yen-Lin Chen , Chia-Hsiu Hsieh

We propose a high-precision phase estimation scheme in a hybrid interferometer by synergistically combining a Kerr nonlinear phase shifter and multi-photon subtraction operations. Using a coherent state and a vacuum state as input…

Quantum Physics · Physics 2026-05-21 Lifen Guo , Qingqian Kang , Zekun Zhao , Jifeng Sun , Teng Zhao , Cunjin Liu , Xin Su , Liyun Hu

Quantum phase estimation is a central primitive in quantum algorithms and sensing, where performance is governed by the sensitivity of measurement signals to the target parameter. While existing methods have developed increasingly…

Quantum Physics · Physics 2026-04-02 Zikang Jia , Suying Liu , Yulong Dong

The discrimination of quantum states is a central problem in quantum information science and technology. Meanwhile, partial post-selection has emerged as a valuable tool for quantum state engineering. In this work, we bring these two areas…

Quantum Physics · Physics 2026-04-14 Qipeng Qian , Christos N. Gagatsos

In this paper, we propose a nonlinear interferometer with feedback loops and explore its efficiency for phase estimation. We analyse two feedback schemes, one where both modes of the interferometer are fed-back into the device and another…

Quantum Physics · Physics 2025-07-24 Shivani Singh , Craig S. Hamilton , Igor Jex

In this paper, we introduce a novel modification to the BB84 Quantum Key Distribution (QKD) protocol, aimed at enhancing its efficiency through the use of quantum memory and delayed measurement. In the standard BB84 protocol, the receiver…

Quantum Physics · Physics 2024-10-29 Mohammed Hassan , Omar Abouelazm

Quantum metrology and quantum sensing aim to use quantum properties to enhance measurement precision beyond what could be classically achieved. Here, we demonstrate how the analysis of the phase space structure of the classical limit of…

Quantum-enhanced phase estimation paves the way to ultra-precision sensing and is of great realistic significance. In this paper we investigate theoretically the estimation of a second-order nonlinear phase shift using a coherent state and…

Quantum Physics · Physics 2019-02-13 Jian-Dong Zhang , Zi-Jing Zhang , Long-Zhu Cen , Jun-Yan Hu , Yuan Zhao

Quantum metrology enables estimation of optical phase shifts with precision beyond the shot-noise limit. One way to exceed this limit is to use squeezed states, where the quantum noise of one observable is reduced at the expense of…

Optical phase estimation is a vital measurement primitive that is used to perform accurate measurements of various physical quantities like length, velocity and displacements. The precision of such measurements can be largely enhanced by…

Quantum metrology can achieve far better precision than classical metrology, and is one of the most important applications of quantum technologies in the real world. To attain the highest precision promised by quantum metrology, all steps…

Quantum Physics · Physics 2021-12-17 Jing Liu , Mao Zhang , Hongzhen Chen , Lingna Wang , Haidong Yuan

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 present geometric-phase microscopy allowing a multipurpose quantitative phase imaging in which the ground-truth phase is restored by quantifying the phase retardance. The method uses broadband spatially incoherent light that is…

Quantum mechanics establishes the ultimate limit to the scaling of the precision on any parameter, by iden- tifying optimal probe states and measurements. While this paradigm is, at least in principle, adequate for the metrology of quantum…