We prove an upper bound proportional to the surface area for the bipartite entanglement of the ground state and thermal states of harmonic oscillator systems with disorder, as measured by the logarithmic negativity. Our assumptions are satisfied for some standard models that are almost surely gapless in the thermodynamic limit.

In this paper, the generating of entanglement by using some biparticle Bose systems acting on vacuum state are investigated. These systems include two-mode squeezed system, thermal system of a free single particle (where the fictitious tilde system is regarded another particle), and the system of two coupling harmonic oscillators. The technique of integration within an ordered product (IWOP) of...

Einstein-Podolsky-Rosen steerability of quantum states is a property that is different from entanglement and Bell nonlocality. We describe the time evolution of a measure that quantifies steerability for arbitrary bipartite Gaussian states in a system consisting of two bosonic modes embedded in a common thermal environment. We work in the framework of the theory of open quantum systems. If the ...

We examine entanglement of thermal states for spin-12 dimers in external magnetic fields. Entanglement transition the temperature-magnetic field plane demonstrates a duality spin-spin interactions. This identifies dual categories symmetric and anti-symmetric with each category classified into toric classes. The line is preserved from class to its class. classification an indication topological ...

Quantum and classical correlations are studied for Werner-Like States of two-qubit cavity system interacting with a thermal reservoir. Starting from Werner-like states, we have shown that entanglement sudden death and decay of both the quantum discord and classical correlation are accelerated by the different factors: thermal photons, cavity decay and the purity of the initial state. By these f...