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Related papers: Exact Steering Bound for Two-Qubit Werner States

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We study the geometric measure of entanglement (GM) of pure symmetric states related to rank-one positive-operator-valued measures (POVMs) and establish a general connection with quantum state estimation theory, especially the maximum…

Quantum Physics · Physics 2011-01-17 Lin Chen , Huangjun Zhu , Tzu-Chieh Wei

Noise is the main source that hinders us from fully exploiting quantum advantages in various quantum informational tasks. However, characterizing and calibrating the effect of noise is not always feasible in practice. Especially for quantum…

Quantum Physics · Physics 2024-03-12 Hyukgun Kwon , Changhun Oh , Youngrong Lim , Hyunseok Jeong , Liang Jiang

Quantum state preparation involves preparing a target state from an initial system, a process integral to applications such as quantum machine learning and solving systems of linear equations. Recently, there has been a growing interest in…

Quantum Physics · Physics 2024-05-08 Shuwen Kan , Miguel Palma , Zefan Du , Samuel A Stein , Chenxu Liu , Juntao Chen , Ang Li , Ying Mao

In the present work, we study the interplay between relativistic effects and quantumness in the system of two relativistic fermions. In particular, we explore entropic measures of quantum correlations and quantum discord before and after…

High Energy Physics - Theory · Physics 2022-12-21 Podist Kurashvili , Levan Chotorlishvili

In this Letter, we mainly investigate the dynamic behavior of quantum steering and how to effectively recover the lost steerability of quantum states within non-Markovian environments. We consider two different cases (one-subsystem or…

Quantum Physics · Physics 2017-12-06 Wen-Yang Sun , Dong Wang , Zhi-Yong Ding , Liu Ye

The problem of deciding whether a set of quantum measurements is jointly measurable is known to be equivalent to determining whether a quantum assemblage is unsteerable. This problem can be formulated as a semidefinite program (SDP).…

A recent result about measurability of a quantum state of a single quantum system is generalized to the case of a single pre- and post-selected quantum system described by a two-state vector. The protection required for such measurement is…

Quantum Physics · Physics 2007-05-23 Y. Aharonov , L. Vaidman

In quantum metrology, measurements are usually treated as passive readout processes. Here we investigate whether post-selected von Neumann measurements (PVNMs) can be used as an active resource to reshape the nonclassical properties of a…

Quantum Physics · Physics 2026-04-21 Janarbek Yuanbek , Bruno Tenorio , Yusuf Turek

It is crucial for various quantum information processing tasks that the state of a quantum system can be determined reliably and efficiently from general quantum measurements. One important class of measurements for this purpose is…

Quantum Physics · Physics 2012-12-17 Gelo Noel M. Tabia

In the device-independent scenario, positive operator-valued measurements (POVMs) can certify more randomness than projective measurements. This paper self-tests a three-outcome extremal qubit POVM in the X-Z plane of the Bloch sphere by…

Quantum Physics · Physics 2024-12-17 Wenjie Wang , Mengyan Li , Fenzhuo Guo , Yukun Wang , Fei Gao

We show how an upper bound for the ability to discriminate any number N of candidates for the Hamiltonian governing the evolution of an open quantum system may be calculated by numerically efficient means. Our method applies an effective…

Quantum Physics · Physics 2018-05-23 Alexander Holm Kiilerich , Klaus Mølmer

Occupying a position between entanglement and Bell nonlocality, Einstein-Podolsky-Rosen (EPR) steering has attracted increasing attention in recent years. Many criteria have been proposed and experimentally implemented to characterize…

Quantum Physics · Physics 2017-11-29 Zhihua Chen , Xiangjun Ye , Shaoming Fei

Quantum measurements can be generalized to include complex quantities. It is possible to relate the quantum weak values of projection operators to the third order Bargmann invariants. The argument of the weak value becomes, up to a sign,…

Quantum Physics · Physics 2021-09-22 Z. Gedik

Determining when the multiparameter quantum Cram\'er--Rao bound (QCRB) is saturable with experimentally relevant single-copy measurements is a central open problem in quantum metrology. Here we establish an equivalence between QCRB…

Quantum Physics · Physics 2026-01-30 Jing Yang , Satoya Imai , Luca Pezzè

Quantum Cognition has delivered a number of models for semantic memory, but to date these have tended to assume pure states and projective measurement. Here we relax these assumptions. A quantum inspired model of human word association…

Neurons and Cognition · Quantitative Biology 2018-03-29 Mojtaba Aliakbarzadeh , Kirsty Kitto

One-qubit pure states, living on the surface of Bloch sphere, can be mapped onto the usual complex plane by using stereographic projection. In this paper, after reviewing the entanglement of two-qubit pure state, it is shown that the…

Quantum Physics · Physics 2016-06-17 Ghader Najarbashi , Bahman Seifi

The optimization conditions for minimum error discrimination of linearly independent pure states comprise of two kinds: stationary conditions over the space of rank one projective measurements and the global maximization conditions. A…

Quantum Physics · Physics 2014-02-20 Tanmay Singal , Sibasish Ghosh

We study the problem of separating the data produced by a given quantum measurement (on states from a memoryless source which is unknown except for its average state), described by a positive operator valued measure (POVM), into a…

Quantum Physics · Physics 2009-11-07 Andreas Winter

A central challenge in quantum metrology is identifying optimal measurements that saturate the quantum Cramer-Rao bound under realistic constraints, e.g., local measurements. We show that symmetries of the probe state provide a general…

Quantum Physics · Physics 2026-03-10 Jia-Xuan Liu , Hai-Long Shi , Chunfeng Wu , Sixia Yu

This paper presents an overview of close parallels that exist between the theory of positive operator-valued measures (POVMs) associated with a separable Hilbert space and the theory of frames on that space, including its most important…

Functional Analysis · Mathematics 2011-11-08 Bill Moran , Stephen Howard , Doug Cochran