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Related papers: Adaptive Optical Phase Estimation Using Time-Symme…

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We investigate critical quantum metrology,that is the estimation of parameters in many-body systems close to a quantum critical point, through the lens of Bayesian inference theory. We first derive a no-go result stating that any…

Quantum Physics · Physics 2023-10-31 Raffaele Salvia , Mohammad Mehboudi , Martí Perarnau-Llobet

We consider application of a temporal imaging system, based on the sum-frequency generation, to a nonclassical, in particular, squeezed optical temporal waveform. We analyze the restrictions on the pump and the phase matching condition in…

Quantum Physics · Physics 2017-04-04 G. Patera , J. Shi , D. B. Horoshko , M. I. Kolobov

Photon counting induces an effective nonlinear optical phase shift on certain states derived by linear optics from single photons. Although this no nlinearity is nondeterministic, it is sufficient in principle to allow scalable linear…

Quantum Physics · Physics 2007-05-23 T. C. Ralph , A. P. Lund , H. M. Wiseman

Quantum phase estimation is one of the key algorithms in the field of quantum computing, but up until now, only approximate expressions have been derived for the probability of error. We revisit these derivations, and find that by ensuring…

Quantum Physics · Physics 2012-02-13 James M. Chappell , Max A. Lohe , Lorenz von Smekal , Azhar Iqbal , Derek Abbott

We investigate the performance of parallel and adaptive quantum channel discrimination strategies for a finite number of channel uses. It has recently been shown that, in the asymmetric setting with asymptotically vanishing type I error…

Quantum Physics · Physics 2024-03-28 Bjarne Bergh , Nilanjana Datta , Robert Salzmann , Mark M. Wilde

In a wide range of applications, the stochastic properties of the observed time series change over time. The changes often occur gradually rather than abruptly: the properties are (approximately) constant for some time and then slowly start…

Methodology · Statistics 2015-04-03 Michael Vogt , Holger Dette

Smoothing is an estimation method whereby a classical state (probability distribution for classical variables) at a given time is conditioned on all-time (both past and future) observations. Here we define a smoothed quantum state for a…

Quantum Physics · Physics 2017-04-25 Ivonne Guevara , Howard Wiseman

We consider a general model of unitary parameter estimation in presence of Markovian noise, where the parameter to be estimated is associated with the Hamiltonian part of the dynamics. In absence of noise, unitary parameter can be estimated…

Quantum Physics · Physics 2018-08-17 R. Demkowicz-Dobrzanski , J. Czajkowski , P. Sekatski

We propose that a pulsed quantum optomechanical system can be applied for the problem of quantum parameter estimation, which targets to yield higher precision of parameter estimation utilizing quantum resource than that using classical…

Quantum Physics · Physics 2016-02-17 Qiang Zheng , Yao Yao , Yong Li

In characterization of quantum systems, adapting measurement settings based on data while it is collected can generally outperform in efficiency conventional measurements that are carried out independently of data. The existing methods for…

Quantum Physics · Physics 2016-11-21 Markku P. V. Stenberg , Frank K. Wilhelm

We introduce a simple protocol for adaptive quantum state tomography, which reduces the worst-case infidelity between the estimate and the true state from $O(N^{-1/2})$ to $O(N^{-1})$. It uses a single adaptation step and just one extra…

We study the simultaneous estimation of multiple phases as a discretised model for the imaging of a phase object. We identify quantum probe states that provide an enhancement compared to the best quantum scheme for the estimation of each…

Quantum Physics · Physics 2013-09-10 Peter C. Humphreys , Marco Barbieri , Animesh Datta , Ian A. Walmsley

Quantum simulation using time evolution in phase estimation-based quantum algorithms can yield unbiased solutions of classically intractable models. However, long runtimes open such algorithms to decoherence. We show how measurement-based…

Quantum Physics · Physics 2022-08-11 Woo-Ram Lee , Zhangjie Qin , Robert Raussendorf , Eran Sela , V. W. Scarola

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and…

Quantum Physics · Physics 2007-05-23 Dominic W. Berry , Howard M. Wiseman

The success of quantum information processing applications relies on accurate and efficient characterization of quantum states, especially nearly-pure states. In this work, we investigate a procedure for adaptive qubit state tomography…

Quantum Physics · Physics 2018-09-05 Aonan Zhang , Yujie Zhang , Feixiang Xu , Long Li , Lijian Zhang

Quantum state and process tomography are typically analyzed under the assumption that devices emit independent and identically distributed (i.i.d.) states or channels. In realistic experiments, however, noise, drift, feedback, or…

Quantum Physics · Physics 2026-02-26 Leonardo Zambrano

Quantum simulation is a cornerstone application for quantum computing, yet standard methods face a trade-off between circuit depth and accuracy: Trotterization depth scales with the number of Hamiltonian terms $L$, while sampling-based…

Quantum Physics · Physics 2026-05-01 Sangjin Lee , Sangkook Choi

Estimating the state of an open quantum system monitored over time requires incorporating information from past measurements (filtering) and, for improved accuracy, also from future measurements (smoothing). While classical smoothing is…

Quantum Physics · Physics 2025-10-10 Mingxuan Liu , Ge Bai , Valerio Scarani

Analog quantum simulation is emerging as a powerful tool for uncovering classically unreachable physics such as many-body real-time dynamics. A complete quantification of uncertainties is necessary in order to make precise predictions using…

Quantum Physics · Physics 2024-05-16 Nikita A. Zemlevskiy , Henry F. Froland , Stephan Caspar

Quantum phase estimation is an important component in diverse quantum algorithms. However, it suffers from spectral leakage, when the reciprocal of the record length is not an integer multiple of the unknown phase, which incurs an accuracy…

Quantum Physics · Physics 2022-05-17 Yifeng Xiong , Soon Xin Ng , Gui-Lu Long , Lajos Hanzo