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Related papers: Coarse Graining Makes It Hard to See Micro-Macro E…

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These two accompanying papers treat two mode entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. Entanglement is a key quantum feature of composite systems where…

Quantum Physics · Physics 2016-06-01 Bryan Dalton , John Goold , Barry Garraway , Margaret Reid

Two very basic constructions involving experimental procedures are the formation of coarse-grained versions of experiments, and the formation of branching sequential experiments. The latter allow for the conditioning of states on the…

Quantum Physics · Physics 2024-10-14 Alex Wilce

Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise,…

Photonic graph states, quantum light states where multiple photons are mutually entangled, are key resources for optical quantum technologies. They are notably at the core of error-corrected measurement-based optical quantum computing and…

We study quantum coarse-grained entropy and demonstrate that the gap in entropy between local and global coarse-grainings is a natural generalization of entanglement entropy to mixed states and multipartite systems. This "quantum…

Quantum Physics · Physics 2020-12-02 Joseph Schindler , Dominik Šafránek , Anthony Aguirre

Two-electron charged self-assembled quantum dot molecules exhibit a decoherence-avoiding singlet-triplet qubit subspace and an efficient spin-photon interface. We demonstrate quantum entanglement between emitted photons and the spin-qubit…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 Yves L. Delley , Martin Kroner , Stefan Fält , Werner Wegscheider , Ataç İmamoğlu

We investigate duality in entanglement of a bipartite multi-photon system generated from a coherent state of light. The system can exhibit polarization entanglement if the two parts are distinguished by their parity, or parity entanglement…

Quantum Physics · Physics 2016-08-17 Su-Yong Lee , Chang-Woo Lee , Pawel Kurzynski , Dagomir Kaszlikowski , Jaewan Kim

The macroscopic limit at which the quantum-to-classical transition occurs remains as one of the long-standing questions in the foundations of quantum theory. There are evidences that the macroscopic limit to which the quantumness of a…

Entangling independent photons is not only of fundamental interest but also of crucial importance for quantum information science. Two-photon interference is a major method to entangle independent identical photons. If two photons are…

Quantum Physics · Physics 2015-01-27 Tian-Ming Zhao , Han Zhang , Jian Yang , Zi-Ru Sang , Xiao Jiang , Xiao-Hui Bao , Jian-Wei Pan

The notion of mutual unbiasedness for coarse-grained measurements of quantum continuous variable systems is considered. It is shown that while the procedure of "standard" coarse graining breaks the mutual unbiasedness between conjugate…

Quantum Physics · Physics 2018-01-25 Daniel S. Tasca , Piero Sánchez , Stephen P. Walborn , Łukasz Rudnicki

Many theoretical and experimental results show that even isolated quantum systems evolving unitarily may equilibrate, since the evolution of some observables may be around an equilibrium value with negligible fluctuations most of the time.…

An entangled quantum state of two or more particles or objects exhibits some of the most peculiar features of quantum mechanics. Entangled systems cannot be described independently of each other even though they may have an arbitrarily…

Mesoscale and Nanoscale Physics · Physics 2018-04-27 C. F. Ockeloen-Korppi , E. Damskagg , J. -M. Pirkkalainen , A. A. Clerk , F. Massel , M. J. Woolley , M. A. Sillanpaa

We analyze and compare three different schemes that can be used to generate entanglement between spin qubits in optically-active single solid-state quantum systems. Each scheme is based on first generating entanglement between the spin…

We propose an experiment where a photon is first cloned by stimulated parametric down-conversion, making many (imperfect) copies, and then the cloning transformation is inverted, regenerating the original photon while destroying the copies.…

Quantum Physics · Physics 2012-03-26 Sadegh Raeisi , Wolfgang Tittel , Christoph Simon

These two accompanying papers treat two mode entanglement for systems of identical massive bosons and the relationship to spin squeezing and other quantum correlation effects. Entanglement is a key quantum feature of composite systems where…

Quantum Physics · Physics 2016-01-07 Bryan Dalton , John Goold , Barry Garraway , Margaret Reid

We consider the quantum cloning of continuous variable entangled states. This is achieved by introducing two symmetric entanglement cloning machines (or e-cloners): a local e-cloner and a global e-cloner; where we look at the preservation…

Quantum Physics · Physics 2009-11-13 Christian Weedbrook , Nicolai B. Grosse , Thomas Symul , Ping Koy Lam , Timothy C. Ralph

Two important results of quantum physics are the \textit{no-cloning} theorem and the \textit{monogamy of entanglement}. The former forbids the creation of an independent and identical copy of an arbitrary unknown quantum state and the…

Quantum Physics · Physics 2021-07-28 Goutam Paul , Soumya Das , Anindya Banerji

Entanglement--one of the most delicate phenomena in nature--is an essential resource for quantum information applications. Large entangled cluster states have been predicted to enable universal quantum computation, with the required single-…

Although the realization of useful quantum computers poses significant challenges, swift progress in emerging quantum technologies is making this goal realistically approachable. In this context, one of the essential resources is quantum…

Quantum Physics · Physics 2022-01-11 Valeria Saggio , Philip Walther

Quantum entanglement is known as a unique feature of quantum mechanics, which cannot be obtained from classical physics. Recently, a coherence interpretation has been conducted for the delayed-choice quantum eraser using coherent photon…

Quantum Physics · Physics 2022-11-22 Byoung S. Ham