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Related papers: Qubit-assisted quantum metrology under a time-reve…

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We derive ultimate precision bounds for estimating parameters encoded in \emph{time-dependent} Hamiltonians in the presence of general Markovian noise, allowing for arbitrary adaptive protocols with fast controls and noiseless ancillas.…

Quantum Physics · Physics 2026-05-19 Luca Previdi , Francesco Albarelli

Quantum metrology is a science about quantum measurements and it plays a key role in precision of quantum parameter estimation. Meanwhile, quantum coherence is an important quantum feature and quantum Fisher information (QFI) is an…

Quantum Physics · Physics 2025-10-30 Jun-Long Zhao , Li Yu , Ming Yang , Chui-Ping Yang

Phase estimation with potentially large phase values, i.e., with large dynamic range, has many applications in quantum metrology, for example to atomic clocks. A recently proposed phase estimation scheme approaches the Heisenberg scaling in…

Quantum Physics · Physics 2026-03-17 Tyler G. Thurtell , Akimasa Miyake

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 typically demands the preparation of exotic quantum probe states, such as entangled or squeezed states, to surpass classical limits. However, the need for carefully calibrated system parameters and finely optimized quantum…

We analyze quantum parameter estimation by studying the dynamics of the quantum Fisher information (QFI) for two classes of parameters, acceleration and initial-state weight, in an Unruh-DeWitt detector undergoing four distinct noninertial…

Quantum Physics · Physics 2025-08-26 Han Wang , Jialin Zhang , Hongwei Yu

We estimate the initial weight and phase parameters ($\theta, \phi)$ of a single qubit system initially prepared in the coherent state $\ket{\theta,\phi}$ and interacts with three different shape of pulses; rectangular, exponential, and…

Quantum Physics · Physics 2017-11-17 N. Metwally , S. S. Hassan

We investigate the ultimate precision achievable in Gaussian quantum metrology. We derive general analytical expressions for the quantum Fisher information matrix and for the measurement compatibility condition, ensuring asymptotic…

Quantum Physics · Physics 2018-07-18 Rosanna Nichols , Pietro Liuzzo-Scorpo , Paul A. Knott , Gerardo Adesso

We present a novel quantum clock synchronization(QCS) scheme of multiple parties which uses operation as the trigger to start the evolution of the initial state, where existing QCS protocols use measurement to start the evolution. Since the…

Quantum Physics · Physics 2015-09-30 Jie-Dong Yue , Yu-Ran Zhang , Heng Fan

Quantum metrology employs quantum resources to achieve measurement precision beyond classical limits. This work investigates a Mach--Zehnder interferometer incorporating a Kerr nonlinear phase shifter, with photon-added two-mode squeezed…

Quantum Physics · Physics 2026-02-20 Zekun Zhao , Qingqian Kang , Teng Zhao , Cunjin Liu , Xin Su , Liyun Hu

We study optimal quantum sensing of multiple physical parameters using repeated measurements. In this scenario, the Fisher information framework sets the fundamental limits on sensing performance, yet the optimal states and corresponding…

Quantum Physics · Physics 2024-04-23 Denis V. Vasilyev , Athreya Shankar , Raphael Kaubruegger , Peter Zoller

Non-Hermitian systems have attracted considerable interest over the last few decades due to their unique spectral and dynamical properties not encountered in Hermitian counterparts. An intensely debated question is whether non-Hermitian…

Quantum Physics · Physics 2026-02-25 Ievgen I. Arkhipov , Franco Nori , Şahin K. Özdemir

Quantum metrology leverages quantum resources such as entanglement and squeezing to enhance parameter estimation precision beyond classical limits. While optimal quantum control strategies can assist to reach or even surpass the Heisenberg…

Quantum Physics · Physics 2025-10-17 Qifei Wei , Shengshi Pang

Quantum Fourier transform (QFT) is a key ingredient of many quantum algorithms where a considerable amount of ancilla qubits and gates are often needed to form a Hilbert space large enough for high-precision results. Qubit recycling reduces…

Quantum-enhanced, idler-free sensing protocol to measure the response of a target object to the frequency of a probe in a noisy and lossy scenario is proposed. In this protocol, a target with frequency-dependent reflectivity embedded in a…

Quantum Physics · Physics 2022-11-15 Mateo Casariego , Yasser Omar , Mikel Sanz

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

Quantum phase estimation (QPE) is a central algorithmic primitive that estimates eigenvalues of a Hamiltonian up to precision $\epsilon$ in Heisenberg-limited time $T=\Theta(1/\epsilon)$. Standard gate-based implementations of QPE require…

Quantum Physics · Physics 2026-05-22 Alexander Schmidhuber , Seth Lloyd

We investigate a probe state preparation protocol based on two non-selective generalized quantum measurements to enhance parameter estimation in single-qubit systems. By fine-tuning the measurement strengths, we demonstrate the ability to…

Quantum Physics · Physics 2026-05-13 Jonas F. G. Santos , Shanhe Su , Moises Rojas

Quantum metrology promises precision beyond classical limits, yet environmental noise typically degrades the quantum resources required for such enhancement. In this work, we investigate frequency estimation in noisy continuous-variable…

Quantum Physics · Physics 2026-05-08 Ayan Patra , Manju , Aditi Sen De , Matteo G. A. Paris

In many-body quantum systems, the quantum Fisher information an observer can obtain is susceptible to decoherence. Consequently, quantum enhanced metrology, such as Heisenberg scaling, cannot usually be achieved. We show, via two distinct…

Quantum Physics · Physics 2022-12-06 Le Hu , Shengshi Pang , Andrew Jordan