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Using the SU($N$) representation of the group theory, we derive the general form of the spin swapping operator for the quantum Heisenberg spin-$s$ systems. We further prove that such a spin swapping operator is equal to the spin singlet…

Quantum Physics · Physics 2009-11-13 Guang-Ming Zhang , Xiaoguang Wang

Entanglement in high-dimensional quantum systems, where one or more degrees of freedom of light are involved, offers increased information capacities and enables new quantum protocols. Here, we demonstrate a functional source of…

In addition to being a workhorse for modern quantum technologies, entanglement plays a key role in fundamental tests of quantum mechanics. The entanglement of photons in multiple levels, or dimensions, explores the limits of how large an…

Quantum Physics · Physics 2018-03-12 Manuel Erhard , Mehul Malik , Anton Zeilinger

In this paper we develop a new approach to the investigation of the bi-partite entanglement entropy in integrable quantum spin chains. Our method employs the well-known replica trick, thus taking a replica version of the spin chain model as…

High Energy Physics - Theory · Physics 2011-02-18 Olalla A. Castro-Alvaredo , Benjamin Doyon

We suggest using the method of quantum annealing for computing the ground state of the Heisenberg spin chains. Our initial Hamiltonian describes a spin system in a highly non-uniform magnetic field. The initial Hamiltonian gradually…

Quantum Physics · Physics 2007-05-23 G. P. Berman , V. N. Gorshkov , V. I. Tsifrinovich

A quantum-mechanical many-particle system may exhibit non-local behavior in that measurements performed on one of the particles can affect a second one that is far apart. These so-called entangled states are crucial for the implementation…

Other Condensed Matter · Physics 2009-11-10 J. M. Bao , A. V. Bragas , J. K. Furdyna , R. Merlin

The spontaneous disentanglement hypothesis is motivated by some outstanding issues in standard quantum mechanics, including the problem of quantum measurement. The current study compares between some possible methods that can be used to…

Quantum Physics · Physics 2026-02-10 Eyal Buks

We consider the non-equilibrium evolution in the spin-1/2 XXZ Heisenberg chain for fixed magnetization after a local quantum quench. This model is equivalent to interacting spinless fermions. Initially an infinite magnetic field is applied…

Strongly Correlated Electrons · Physics 2012-02-20 Martin Ganahl , Elias Rabel , Fabian H. L. Essler , Hans Gerd Evertz

The Pryce (e) spin and position operators of the quantum theory of Dirac's free field were re-defined and studied recently with the help of a new spin symmetry and suitable spectral representations [I. I. Cot\u aescu, Eur. Phys. J. C (2022)…

Quantum Physics · Physics 2024-11-04 Ion I. Cotaescu

Quantum entanglement is the characteristic quantum correlation. Here we use this concept to analyze the quantum entanglement generated by Schwinger production of particle-antiparticle pairs in an electric field, as well as the change of…

High Energy Physics - Theory · Physics 2017-02-15 Yujie Li , Yue Dai , Yu Shi

Motivated by some well-known results in the phase space description of quantum optics and quantum information theory, we aim to describe the formalism of quantum field theory by explicitly considering the holomorphic representation for a…

Quantum Physics · Physics 2020-10-28 Jasel Berra-Montiel , Alberto Molgado

Using group-theoretical approach we found a family of four nine-parameter quantum states for the two-spin-1/2 Heisenberg system in an external magnetic field and with multiple components of Dzyaloshinsky-Moriya (DM) and…

Quantum Physics · Physics 2021-05-13 A. V. Fedorova , M. A. Yurischev

The purpose of this paper is to study entanglement of quantum states by means of Schmidt decomposition. The notion of Schmidt information which characterizes the non-randomness of correlations between two observers that conduct measurements…

Quantum Physics · Physics 2007-05-23 A. Yu. Bogdanov , Yu. I. Bogdanov , K. A. Valiev

Identical particles and entanglement are both fundamental components of quantum mechanics. However, when identical particles are condensed in a single spatial mode, the standard notions of entanglement, based on clearly identifiable…

Quantum Physics · Physics 2014-04-23 N. Killoran , M. Cramer , M. B. Plenio

Field mediated entanglement experiments probe the quantum superposition of macroscopically distinct field configurations. We show that this phenomenon can be described by using a transparent quantum field theoretical formulation of…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Lin-Qing Chen , Flaminia Giacomini , Carlo Rovelli

In quantum physics, even simple data with a well-defined structure at the wave function level can be characterized by extremely complex correlations between its constituent elements. The inherent non-locality of the quantum correlations…

Entanglement, a fundamental phenomenon of quantum theory, has recently been observed in processes in high-energy physics. This opens new avenues for probing quantum effects in relativistic regimes, but also poses conceptual and technical…

High Energy Physics - Phenomenology · Physics 2026-05-01 Hai-Chau Nguyen , Gilberto Tetlalmatzi-Xolocotzi , Carmen Diez Pardos , Otfried Gühne , Matthias Kleinmann

We study the tomography of multispin quantum states in the context of finite-dimensional Wigner representations. An arbitrary operator can be completely characterized and visualized using multiple shapes assembled from linear combinations…

Quantum Physics · Physics 2018-01-16 David Leiner , Robert Zeier , Steffen J. Glaser

We have found a quantum cloning machine that optimally duplicates the entanglement of a pair of $d$-dimensional quantum systems. It maximizes the entanglement of formation contained in the two copies of any maximally-entangled input state,…

Quantum Physics · Physics 2007-05-23 E. Karpov , P. Navez , N. J. Cerf

This paper reviews quantum spin squeezing, which characterizes the sensitivity of a state with respect to an SU(2) rotation, and is significant for both entanglement detection and high-precision metrology. We first present various…

Quantum Physics · Physics 2011-11-29 Jian Ma , Xiaoguang Wang , C. P. Sun , Franco Nori