in this paper we studied the thermal negativity in a two-qubit xx spin ½ chain model and xxx spin1/2 chain model(isotropic heisenberg model)spin-1/2 chain subjected to an external magnetic field inz direction. we calculate analytical relation for the thermal negativity for two qubit xx and xxx spinchain models in the external magnetic field. effects of the magnetic field and temperature on then...

In this paper we studied the thermal negativity in a two-qubit XX spin ½ chain model and XXX spin1/2 chain model(isotropic Heisenberg model)spin-1/2 chain subjected to an external magnetic field inz direction. We calculate analytical relation for the thermal negativity for two qubit XX and XXX spinchain models in the external magnetic field. Effects of the magnetic field and temperature on then...

in the present work we use the negativity to study the effect of rashba parameter on the thermal entanglement ofelectronic spin and subband states inside a quasi-one-dimensional rashba nanowire, in a perpendicular uniformmagnetic field. we assume that the nanowire is held at a temperature t, so that both spin and subband states, withdefinite probabilities, are present. the partially transposed ...

in this work we investigate the thermal entanglement between two-level atoms and photons in a nonlinear cavity. we consider intensity-dependent couplings and calculate the negativity, as a measure of atom-photonentanglement. the cavity is assumed to be at a temperature t, so that all number of photons, and at the same time, both atomic states, with definite probabilities, are present. we then d...

We explore entanglement negativity, a measure of the distillable entanglement contained in a quantum state, in relativistic field theories in various dimensions. We first give a general overview of negativity and its properties and then explain a well known result relating (logarithmic) negativity of pure quantum states to the Rényi entropy (at index 1/2), by exploiting the simple features of e...

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 the effects of nonlinear couplings and external magnetic field on the thermal entanglement in a two-spin-qutrit system by applying the concept of negativity. It is found that the nonlinear couplings favor the thermal entanglement creating. Only when the nonlinear couplings |K| are larger than a certain critical value does the entanglement exist. The dependence of the thermal enta...

we study the dynamics of two three-level atoms interacting with independent bosonic lorentzian reservoirs at zero temperature. such systems can be created in far astronomical objects. quantum mechanical behaviour of these particles can produce detectable effects on the spectroscopic identifications of these objects, if such behaviour remain stable during the interaction with their media. it is ...

In the present work we use the negativity to study the effect of Rashba parameter on the thermal entanglement of electronic spin and subband states inside a quasi-one-dimensional Rashba nanowire, in a perpendicular uniform magnetic field. We assume that the nanowire is held at a temperature T, so that both spin and subband states, with definite probabilities, are present. The partially transpos...

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.