Thermal Entanglement of Spins in an Inhomogeneous MagnetIc field

Abstract

We investigate the thermal entanglement for the Heisenberg XXX model in an external inhomogeneous magnetic field by using negativity. We further exploit a measure called quantum mixedness to study t he interaction of our system of spins with the heat bath. We study the properties of thermal entanglement by parametrically controlling the inhomogeneous magnetic field on an individual spin. It is noted that the variation in entanglement is symmetric around the applied magnetic field. In the ferromagnetic case, introducing even a small amount of inhomogeneities in the magnetic field can lead to the production of significant thermal entanglement which shows that t he thermal entanglement is highly unstable in a given case.