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Related papers: Fidelity for imperfect postselection

200 papers

We analyze mean fidelity between random density matrices of size N, generated with respect to various probability measures in the space of mixed quantum states: Hilbert-Schmidt measure, Bures (statistical) measure, the measures induced by…

Quantum Physics · Physics 2009-11-10 Karol Zyczkowski , Hans-Jurgen Sommers

Fidelity is the standard measure for quantifying the similarity between two quantum states. It is equal to the square of the minimum Bhattacharyya coefficient between the probability distributions induced by quantum measurements on the two…

Quantum Physics · Physics 2025-12-01 Datong Chen , Huangjun Zhu

We formulate an algorithm to lower bound the fidelity between quantum many-body states only from partial information, such as the one accessible by few-body observables. Our method is especially tailored to permutationally invariant states,…

Quantum Physics · Physics 2020-08-19 Matteo Fadel , Albert Aloy , Jordi Tura

In this work, the measurement transition as well as precision measurement advantages of single-photon-added coherent state after postselected von Neumann measurement are investigated. We noticed that the weak-to-strong measurement…

Quantum Physics · Physics 2023-01-27 Yusuf Turek , Akbar Islam , Ahmad Abliz

In this paper, by providing a class of coherence measures in finite dimensional systems, a sufficient and necessary condition for the existence of coherence transformations that convert one probability distribution of any pure states into…

Quantum Physics · Physics 2015-05-28 Xiaofei Qi , Zhaofang Bai , Shuanping Du

We address the interaction of two Gaussian states interferring at a beam splitter and analyze the correlations exhibited by the resulting bipartite system. We demonstrate that nonlocal correlations (entanglement) arise if and only if the…

Quantum Physics · Physics 2015-05-27 Stefano Olivares , Matteo G. A. Paris

Weak measurements with mixed probe states were investigated in the presence of noise in the probe system. We show that the completely mixed state can be used as a probe state for weak measurements of imaginary weak values. The completely…

Quantum Physics · Physics 2012-11-20 Shuhei Tamate , Toshihiro Nakanishi , Masao Kitano

We present a new measure of entanglement for mixed states. It can be approximately computable for every state and can be used to quantify all different types of multipartite entanglement. We show that it satisfies the usual properties of a…

Quantum Physics · Physics 2007-05-23 Fernando G. S. L. Brandao , Reinaldo O. Vianna

We describe a simple method for certifying that an experimental device prepares a desired quantum state rho. Our method is applicable to any pure state rho, and it provides an estimate of the fidelity between rho and the actual (arbitrary)…

Quantum Physics · Physics 2011-06-09 Steven T. Flammia , Yi-Kai Liu

We give a simple way of characterising the average fidelity between a unitary and a general operation on a single qubit which only involves calculating the fidelities for a few pure input states.

Quantum Physics · Physics 2007-05-23 M. D. Bowdrey , D. K. L. Oi , A. J. Short , J. A. Jones

We experimentally investigate a strategy to discriminate between quaternary phase-shift keyed coherent states based on single-shot measurements that is compatible with high-bandwidth communications. We extend previous theoretical work in…

Quantum Physics · Physics 2018-03-21 M. T. DiMario , E. Carrasco , R. A. Jackson , F. E. Becerra

We investigate the effectiveness of entanglement detection based on multiple fidelities via the geometry of the joint separable numerical range. When all reference states are product states, we derive a necessary and sufficient criterion…

Quantum Physics · Physics 2026-05-26 Pei Li , Bang-Hai Wang

Recently, the much-used trace distance of coherence was shown to not be a proper measure of coherence, so a modification of it was proposed. We derive an explicit formula for this modified trace distance of coherence on pure states. Our…

Quantum Physics · Physics 2019-05-30 Nathaniel Johnston , Chi-Kwong Li , Sarah Plosker

We study the combined counting statistics of two capacitively coupled transport channels. In particular, we examine the conditions necessary for utilizing one channel as detector sensitive to the occupation of the other. A good detector…

Mesoscale and Nanoscale Physics · Physics 2010-07-19 Gernot Schaller , Gerold Kiesslich , Tobias Brandes

The fidelity (Shannon mutual information between measurements and physical quantities) is proposed as a quantitative measure of the quality of physical measurements. The fidelity does not depend on the true value of unknown physical…

Quantum Physics · Physics 2011-03-15 Thomas B. Bahder

The implementation of weak-value amplification requires the pre- and post-selection of states of a quantum system, followed by the observation of the response of the meter, which interacts weakly with the system. Data acquisition from the…

Quantum Physics · Physics 2015-06-17 G. Bié Alves , B. M. Escher , R. L. de Matos Filho , N. Zagury , L. Davidovich

In this paper we propose measurement induced nonlocality (MIN) using a metric based on fidelity to capture global nonlocal effect of a quantum state due to locally invariant projective measurements. This quantity is a remedy for local…

Quantum Physics · Physics 2017-09-13 R. Muthuganesan , R. Sankararnarayanan

In this paper for a class of symmetric multiparty pure states we consider a conjecture related to the geometric measure of entanglement: 'for a symmetric pure state, the closest product state in terms of the fidelity can be chosen as a…

Quantum Physics · Physics 2009-12-31 Masahito Hayashi , Damian Markham , Mio Murao , Masaki Owari , Shashank Virmani

The ability to post-select the outcomes of an experiment is a useful theoretical concept and experimental tool. In the context of weak measurements post-selection can lead to surprising results such as complex weak values outside the range…

Quantum Physics · Physics 2014-06-09 Dawei Lu , Aharon Brodutch , Jun Li , Hang Li , Raymond Laflamme

Conformal inference has played a pivotal role in providing uncertainty quantification for black-box ML prediction algorithms with finite sample guarantees. Traditionally, conformal prediction inference requires a data-independent…

Methodology · Statistics 2023-07-04 Siddhaarth Sarkar , Arun Kumar Kuchibhotla