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Related papers: Bipartite entanglement harvesting with multiple de…

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Multipartite entanglement is a key resource for quantum computation. It is expected theoretically that entanglement transition may happen for multipartite random quantum states, however, which is still absent experimentally. Here, we report…

We study correlations between two Unruh-DeWitt detectors coupled to a scalar field in a cylindrical cavity. Boundary conditions strongly modify the detector-correlation dynamics relative to free space. The entanglement negativity is…

Quantum Physics · Physics 2026-05-28 Shagun Kaushal , Harkirat Singh Sahota

We explore entanglement harvesting using two Unruh-DeWitt (UDW) detectors linearly coupled to the scalar density of a massless spin-1/2 field in 1+1 Schwarzschild spacetime. We consider different vacua, including the Boulware,…

General Relativity and Quantum Cosmology · Physics 2025-08-04 Nitesh Kumar Dubey , Sanved Kolekar

We analyze the interactions of particle detectors with coherent states of a free scalar field. We find that the eigenvalues of the post-interaction density matrices of i) a single detector, ii) two detectors, and iii) the partial transpose…

Quantum Physics · Physics 2021-12-07 Petar Simidzija , Eduardo Martin-Martinez

We investigate the features of the entanglement spectrum (distribution of the eigenvalues of the reduced density matrix) of a large quantum system in a pure state. We consider all R\'enyi entropies and recover purity and von Neumann entropy…

Quantum Physics · Physics 2019-09-20 Paolo Facchi , Giorgio Parisi , Saverio Pascazio , Antonello Scardicchio , Kazuya Yuasa

We propose a hybrid approach to the experimental assessment of the genuine quantum features of a general system consisting of microscopic and macroscopic parts. We infer entanglement by combining dichotomic measurements on a bidimensional…

Quantum entanglement is an essential resource for quantum science and technology. However, entanglement detection and quantification, via typical entanglement measures such as linear entanglement entropy or negativity, can be a very…

Quantum Physics · Physics 2025-06-17 Diego Fallas Padilla , Mingjian Zhu , Han Pu

We study entanglement in a system of three coupled quantum harmonic oscillators. Specifically, we use the Schmidt decomposition to analyze how the entanglement is distributed among the three subsystems. The Schmidt decomposition is a…

Quantum Physics · Physics 2024-09-30 Abdeldjalil Merdaci , Ahmed Jellal

Recently, a toolkit of highly symmetric techniques employing matrix inequalities has been developed to detect entanglement in various ways. Here we unifiedly explain in detail these methods, and expand them to a new family of positive maps…

Quantum Physics · Physics 2026-02-10 Albert Rico

We study the properties of the transition probability for a circularly accelerated detector that interacts with the massless scalar fields in the presence of a reflecting boundary. As the trajectory radius increases, the transition…

Quantum Physics · Physics 2025-03-28 Runhu Li , Zixu Zhao

In recent years considerable progress has been made towards developing a general theory of quantum entanglement. In particular, criteria to decide whether a given quantum state is entangled are of high theoretical and practical interest.…

Quantum Physics · Physics 2025-01-27 Shruti Aggarwal

High-dimensional entanglement has been identified as an important resource in quantum information processing, and also as a main obstacle for simulating quantum systems. Its certification is often difficult, and most widely used methods for…

Quantum Physics · Physics 2024-01-31 Shuheng Liu , Matteo Fadel , Qiongyi He , Marcus Huber , Giuseppe Vitagliano

In the context of entanglement in relativistic $2\to 2$ scattering described by a perturbative $S$-matrix, we derive analytically the concurrence for a mixed final state of two qubits corresponding to a discrete quantum number of the…

High Energy Physics - Phenomenology · Physics 2026-04-08 Kamila Kowalska , Enrico Maria Sessolo

We study the relationship between entanglement and parametric resonance in a system of two coupled time-dependent oscillators. As a measure of bipartite entanglement, we calculate the linear entropy for the reduced density operator, from…

Quantum Physics · Physics 2011-08-19 V. M. Bastidas , J. H. Reina , C. Emary , T. Brandes

We review recent results regarding entanglement in quantum fields in cosmological spacetimes and related phenomena in flat spacetime such as the Unruh effect. We being with a summary of important results about field entanglement and the…

Quantum Physics · Physics 2014-10-29 Eduardo Martin-Martinez , Nicolas C. Menicucci

Among all entanglement measures negativity arguably is the best known and most popular tool to quantify bipartite quantum correlations. It is easily computed for arbitrary states of a composite system and can therefore be applied to discuss…

Quantum Physics · Physics 2014-09-19 Christopher Eltschka , Jens Siewert

We consider entanglement detection for quantum key distribution systems that use two signal states and continuous variable measurements. This problem can be formulated as a separability problem in a qubit-mode system. To verify…

Quantum Physics · Physics 2007-05-23 Johannes Rigas , Otfried Gühne , Norbert Lütkenhaus

We show how the use of entanglement can enhance the precision of the detection of the Unruh effect with an accelerated probe. We use the Unruh-DeWitt model of a two-level atom interacting relativistically with a quantum field and treat the…

Quantum Physics · Physics 2017-01-30 Zehua Tian , Jieci Wang , Jiliang Jing , Andrzej Dragan

We propose a new type of the Unruh-DeWitt detector which measures the decoherence of the reduced density matrix of the detector interacting with the massless quantum scalar field. We find that the decoherence decay rates are different in…

General Relativity and Quantum Cosmology · Physics 2020-11-18 Alexander I Nesterov , Gennady P Berman , Manuel A Rodríguez Fernández , Xidi Wang

The problem of entanglement detection is a long standing problem in quantum information theory. One of the primary procedures of detecting entanglement is to find the suitable positive but non-completely positive maps. Here we try to give a…