An approach is presented that can also account for the description of small ferromagnetic particle magnetization tunneling. An estimate of the saturation value of an external applied magnetic field along the easy axis is obtained. An analytic expression for the tunneling factor in the absence of...

We propose an approach which allows one to construct and use a potential function written in terms of an angle variable to describe interacting spin systems. We show how this can be implemented in the Lipkin–Meshkov–Glick, here considered a paradigmatic spin model. It is shown how some...