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Non-Gaussian entangled states play a crucial role in harnessing quantum advantage in continuous-variable quantum information. However, how to fully characterize N-partite (N > 3) non-Gaussian entanglement without quantum state tomography…

Quantum Physics · Physics 2023-12-05 Da Zhang , David Barral , Yanpeng Zhang , Kamel Bencheikh

We demonstrate how to efficiently derive a broad class of inequalities for entanglement detection in multi-mode continuous variable systems. The separability conditions are established from partial transposition (PT) in combination with…

Quantum Physics · Physics 2015-05-13 Qingqing Sun , Hyunchul Nha , M. Suhail Zubairy

Hamiltonian Mechanics works for conserved systems and Quantum Mechanics is given in Hamiltonian language. It is considered that complexifying the quantum Hamiltonian, a balanced loss and gain model can be created. The usual mathematics of…

General Physics · Physics 2015-12-03 Chetan Waghela

As a hallmark of pure quantum effect, quantum entanglement has provided unconventional routes to condensed matter systems. Here, from the perspective of quantum entanglement, we disclose exotic quantum physics in non-Hermitian…

Mesoscale and Nanoscale Physics · Physics 2022-03-30 Li-Mei Chen , Yao Zhou , Shuai A. Chen , Peng Ye

We examine the implications of several recently derived conditions [Hillery and Zubairy, Phys. Rev. Lett. 96, 050503 (2006)] for determining when a two-mode state is entangled. We first find examples of non-Gaussian states that satisfy…

Quantum Physics · Physics 2009-11-13 Mark Hillery , M. Suhail Zubairy

We discuss an implementation of the entanglement witness, a method to detect entanglement with few local measurements, in systems where entangled electrons are generated both in the spin and orbital degrees of freedom. We address the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Lara Faoro , Fabio Taddei

We present methods for detecting entanglement around symmetric Dicke states. In particular, we consider N-qubit symmetric Dicke states with N/2 excitations. In the first part of the paper we show that for large N these states have the…

Quantum Physics · Physics 2007-05-23 Geza Toth

The efficient witnessing and certification of entanglement is necessitated by its ubiquitous use in various aspects of quantum technologies. In the case of continuous-variable bipartite systems, the Shchukin--Vogel hierarchy gives necessary…

Quantum Physics · Physics 2025-09-09 Elena Callus , Martin Gärttner , Tobias Haas

This paper gives a criterion for detecting the entanglement of a quantum state, and uses it to study the relationship between topological and quantum entanglement. It is fundamental to view topological entanglements such as braids as…

Quantum Physics · Physics 2009-11-10 Louis H. Kauffman , Samuel J. Lomonaco

Since Fermions are based on anti-commutation relations, their entanglement can not be studied in the usual way, such that the available theory has to be modified appropriately. Recent publications consider in particular the structure of…

Quantum Physics · Physics 2008-12-04 M. Keyl

We propose an ordered set of experimentally accessible conditions for detecting entanglement in mixed states. The $k$-th condition involves comparing moments of the partially transposed density operator up to order $k$. Remarkably, the…

We provide the first solution of a time-dependent metric operator for the non-Hermitian Jaynes-Cummings Hamiltonian. We use this solution to calculate the entanglement between two identical isolated such Hamiltonians. The presence of a…

Quantum Physics · Physics 2020-12-02 Thomas Frith

Entanglement harvesting from the quantum field is a well-known fact that, in recent times, is being rigorously investigated further in flat and different curved backgrounds. The usually understood formulation studies the possibility of two…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Dipankar Barman , Subhajit Barman , Bibhas Ranjan Majhi

We present techniques to construct the Deutsch-Hayden representation for quantum field operators and apply them to an entangled state of identical nonrelativistic spin-1/2 fermions localized in well-separated spatial regions. Using these…

Quantum Physics · Physics 2023-01-11 Mark A. Rubin

We demonstrate how to discriminate two non-orthogonal, entangled quantum state which are slightly different from each other by using pseudo-Hermitian system. The positive definite metric operator which makes the pseudo-Hermitian systems…

Quantum Physics · Physics 2015-06-04 Ananya Ghatak , Bhabani Prasad Mandal

We derive a hierarchy of continuous-variable multipartite entanglement conditions in terms of second-order moments of position and momentum operators that generalizes existing criteria. Each condition corresponds to a convex optimization…

Quantum Physics · Physics 2015-11-04 E. Shchukin , P. van Loock

We present an approach to estimate the operational distinguishability between an entangled state and any separable state directly from measuring an entanglement witness. We show that this estimation also implies bounds on a variety of other…

Quantum Physics · Physics 2024-04-01 Liang-Liang Sun , Xiang Zhou , Armin Tavakoli , Zhen-Peng Xu , Sixia Yu

We extend the definition of entanglement witnesses based on structure factors to the case in which the position of the scatterers is quantized. This allows us to study entanglement detection in hybrid systems. We provide several examples…

Quantum Physics · Physics 2015-06-19 Massimo Borrelli , Matteo Rossi , Chiara Macchiavello , Sabrina Maniscalco

We present a development of a geometric approach to entanglement indicators. The method is applied to detect genuine multiqubit entanglement. The criteria are given in form of non-linear conditions imposed on correlation tensors. Thus they…

Quantum Physics · Physics 2015-05-30 Wieslaw Laskowski , Marcin Markiewicz , Tomasz Paterek , Marek Zukowski

We present four estimators of the entanglement (or interdepency) of ground-states in which the coefficients are all real nonnegative and therefore can be interpreted as probabilities of configurations. Such ground-states of hermitian and…

Statistical Mechanics · Physics 2009-09-28 F. C. Alcaraz , V. Rittenberg , G. Sierra