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...

Quantum entanglement is an important prediction of quantum mechanics and constitutes indeed a valuable resource in quantum information processing [1]. Much efforts are devoted to the study and characterization of it. Very recently one kind of natural entanglement, the thermal entanglement [2–7], is proposed and investigated. The investigations of this type of entanglement, groundstate entanglem...

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...

The sensitivity of entanglement to the thermal and squeezed reservoirs’ parameters is investigated regarding entanglement decay and what is called sudden-death of entanglement, ESD, for a system of two qubit pairs. The dynamics of information is investigated by means of the information disturbance and exchange information. We show that for squeezed reservoir, we can keep both of the entanglemen...

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum entanglement and quantum discord for a system consisting of two non-interacting modes embedded in a thermal environment. Entanglement and discord are used to quantify the quantum correlations of the system. For all values of the tempe...

We study the change of entanglement under general linear transformation of modes in a bosonic system and determine the conditions under which entanglement can be generated under such transformations. As an example we consider the thermal entanglement between the vibrational modes of two coupled oscillators and determine the temperature above which quantum correlations are destroyed by thermal f...

We study the effect of nonuniformities in the magnetic field on the thermal entanglement of a two spin system. We show that in the ferromagnetic case a very small nonuniformity is capable to produce large values of thermal entanglement. In the antiferromagnetic case, nonuniformity only slightly raises the threshold temperature, but lowers the value of entanglement.

Small self-contained quantum thermal machines function without external source of work or control but using only incoherent interactions with thermal baths. Here we investigate the role of entanglement in a small self-contained quantum refrigerator. We first show that entanglement is detrimental as far as efficiency is concerned-fridges operating at efficiencies close to the Carnot limit do not...

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the continuous-variable quantum correlations (quantum entanglement and quantum discord) for a system consisting of two noninteracting bosonic modes embedded in a thermal environment. We solve the Kossakowski-Lindblad master equation for the time evolution of the con...