  Skyrmions have become one of the most visited topics during the last decade
in condensed matter physics. In this work, and by means of analytical
calculations and micromagnetic simulations, we explore the effect of the
magnetostatic field generated by a magnetic tip on the stability of skyrmions.
Our results show that the interaction energy between the tip and the skyrmion
plays a fundamental role in the stabilization of N\'eel skyrmions confined in
nanodisks, allowing its nucleation and annihilation, and also providing precise
control of its size and polarity. Based on our results, we propose a very
simple and cyclic method to nucleate and annihilate skyrmions, as well as to
control their polarity and chirality. This proposal could open new
possibilities for logic devices taking advantage of all the degrees of freedom
that skyrmionic textures have.
