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Related papers: SIC-POVMs and Compatibility among Quantum 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

Similarly to quantum states, also quantum measurements can be "mixed", corresponding to a random choice within an ensemble of measuring apparatuses. Such mixing is equivalent to a sort of hidden variable, which produces a noise of purely…

Quantum Physics · Physics 2007-05-23 Giacomo Mauro D'Ariano , Paoloplacido Lo Presti , Paolo Perinotti

Symmetry is a unifying concept in physics. In quantum information and beyond, it is known that quantum states possessing symmetry are not useful for certain information-processing tasks. For example, states that commute with a Hamiltonian…

Quantum Physics · Physics 2023-09-27 Margarite L. LaBorde , Soorya Rethinasamy , Mark M. Wilde

Sufficient and necessary conditions are presented for the existence of $(N,M)$-positive operator valued measures ($(N,M)$-POVMs) valid for arbitrary-dimensional quantum systems. A sufficient condition for the existence of $(N,M)$-POVMs is…

Quantum Physics · Physics 2023-10-20 Maximilian Schumacher , Gernot Alber

This thesis aims to establish notions of symmetry for quantum states and channels as well as describe algorithms to test for these properties on quantum computers. Ideally, the work will serve as a self-contained overview of the subject. We…

Quantum Physics · Physics 2023-05-25 Margarite L. LaBorde

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

We introduce and explore two questions concerning spectra of operators that are of interest in the theory of entanglement in symmetric (i.e., bosonic) quantum systems. First, we investigate the inverse eigenvalue problem for symmetric…

Quantum Physics · Physics 2022-05-27 Gabriel Champagne , Nathaniel Johnston , Mitchell MacDonald , Logan Pipes

Several central problems in quantum information theory (such as measurement compatibility and quantum steering) can be rephrased as membership in the minimal matrix convex set corresponding to special polytopes (such as the hypercube or its…

Quantum Physics · Physics 2024-01-23 Andreas Bluhm , Ion Nechita , Simon Schmidt

Two-mode cavities can be prepared in quantum states which represent symmetric multi-qubit states. However, the qubits are impossible to address individually and as such cannot be independently measured or otherwise manipulated. We propose…

Quantum Physics · Physics 2009-11-07 Daniel E. Browne , Martin B. Plenio

We analyze bipartite quantum states that admit a symmetric extension. Any such state can be decomposed into a convex combination of states that allow a _pure_ symmetric extension. A necessary condition for a state to admit a pure symmetric…

Quantum Physics · Physics 2009-06-10 Geir Ove Myhr , Norbert Lütkenhaus

In relation of observable and quantum state, the entity $I_C$ from previous work quantifies simultaneously coherence, incompatibility and quantumness. In this article its application to quantum correlations in bipartite states is studied.…

Quantum Physics · Physics 2007-05-23 Fedor Herbut

We develop a rigorous connection between statistical properties of an interference pattern and the coherence properties of the underlying quantum state. With explicit examples, we demonstrate that even for inaccurate reconstructions of…

Quantum Physics · Physics 2015-11-25 Kai von Prillwitz , Łukasz Rudnicki , Florian Mintert

The state that an observer attributes to a quantum system depends on the information available to that observer. If two or more observers have different information about a single system, they will in general assign different states. Is…

Quantum Physics · Physics 2007-05-23 Todd A. Brun

Incompatibility of quantum measurements is of fundamental importance in quantum mechanics. It is closely related to many nonclassical phenomena such as Bell nonlocality, quantum uncertainty relations, and quantum steering. We study the…

Quantum Physics · Physics 2020-01-01 Lin Zhang , Hua Xiang , Xianqing Li-Jost , Shao-Ming Fei

We introduce a generalization of symmetric measurements to collections of unequinumerous positive, operator-valued measures (POVMs). For informationally complete sets, we propose construction methods from orthonormal Hermitian operator…

Quantum Physics · Physics 2024-12-16 Katarzyna Siudzińska

We examine the geometric structure of qutrit state space by identifying the outcome probabilities of symmetric informationally complete (SIC) measurements with quantum states. We categorize the infinitely many qutrit SICs into eight SIC…

Quantum Physics · Physics 2013-08-01 Gelo Noel M. Tabia , D. M. Appleby

Informationally complete measurements are a dramatic discovery of quantum information science, and the symmetric IC measurements, known as SICs, are in many ways optimal among them. Close study of three of the "sporadic SICs" reveals an…

Quantum Physics · Physics 2018-07-20 Blake C. Stacey

Studies on symmetric extendibility of quantum states become especially important in a context of analysis of one-way quantum measures of entanglement, distilabillity and security of quantum protocols. In this paper we analyse composite…

Quantum Physics · Physics 2016-09-21 Marcin L. Nowakowski

The quantum measurement incompatibility is a distinctive feature of quantum mechanics. We investigate the incompatibility of a set of general measurements and classify the incompatibility by the hierarchy of compatibilities of its subsets.…

Quantum Physics · Physics 2020-02-03 Bao-Zhi Sun , Zhi-Xi Wang , Xianqing Li-Jost , Shao-Ming Fei

Coherence is a cornerstone of quantum theory and a prerequisite for the advantage of quantum technologies. In recent work, the notion of coherence with respect to a general quantum measurement (POVM) was introduced and embedded into a…

Quantum Physics · Physics 2021-03-31 Felix Bischof , Hermann Kampermann , Dagmar Bruß