In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous variable entanglement for a system consisting of two non-interacting bosonic modes embedded in two independent thermal environments. By using the Peres-Simon necessary and sufficient criterion for separability of two-mode Gaussian states, we describe ...

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous variable entanglement for a system consisting of two non-interacting bosonic modes embedded in two independent thermal environments. By using the Peres-Simon necessary and sufficient criterion for separability of two-mode Gaussian states, we describe ...

We study the effect of inhomogeneities in the magnetic field on the thermal entanglement of a two spin system. We show that in the ferromagnetic case a very small inhomogeneity is capable to produce large values of thermal entanglement. This shows that the absence of entanglement in the ferromagnetic Heisenberg system is highly unstable against inhomogeneoity of magnetic fields which is inevita...

We study the thermal quantum correlations and entanglement in spin1 Bose-Hubbard model with two and three particles. While we use negativity to calculate entanglement, more general non-classical correlations are quantified using a new measure based on a necessary and sufficient condition for zero-discord state. We demonstrate that the energy level crossings in the ground state of the system are...

We investigate a possible scheme for entangling two mode thermal fields through the quantum erasing process, in which an atom is coupled with two mode fields via the interaction governed by the two-mode two-photon Jaynes-Cummings model. The influence of phase decoherence on the entanglement of two mode fields is discussed. It is found that quantum erasing process can transfer part of entangleme...

We study the entanglement in the quantum Heisenberg XY model in which the so-called W entangled states can be generated for 3 or 4 qubits. By the concept of concurrence, we study the entanglement in the time evolution of the XY model. We investigate the thermal entanglement in the two-qubit isotropic XY model with a magnetic field and in the anisotropic XY model, and find that the thermal entan...

The effects of the temperature were taken into account and some authors used thermal entanglement to study the electron spin system or other models at finite temperature in Refs.[2,3,4]. For example, X.G. Wang investigated the isotropic Heisenberg XXX model at finite temperature[3]. Y. Sun et al. investigated the thermal entanglement in the two-qubit Heisenberg XY model in nonuniform magnetic f...

In this work we study the dynamics of the maximum extractable entanglement for a system composed of two qubits interacting either with two independent thermal baths, a common thermal bath or a common squeezed bath. The states with maximum entanglement are found applying filtering operations which transform each state to a state in Bell diagonal form. We observe a revival of the maximum extracta...

Over the past few years much effort has been put into studying the entanglement of multipartite systems both qualitatively and quantitatively. Entangled states constitute a valuable resource in quantum information processing [1]. Quite recently, entanglement in quantum operations [2–4] and entanglement in indistinguishable fermionic and bosonic systems [5–7] have been considered. Entanglement i...

The upper and lower bounds of entanglement of formation are given for two mode squeezed thermal state. The bounds are compared with other entanglement measure or bounds. The entanglement distillation and the relative entropy of entanglement of infinitive squeezed state are obtained at the postulation of hashing inequality.