Magnetic monopoles have never been observed outside the abstract realm of theoretical physics. There is no way to make one.
There are, however, quasiparticles that act as monopole analogues. This means there are particles that aren’t really particles that act like monopoles that aren’t really monopoles.
Magnets, as we know them to exist, have a north pole and a south pole at opposing ends. If that magnet is cut in half, each half would retain the quality of one north pole and one south pole. A monopole magnet has only one pole; a north with no south or a south with no north.
Alberto Bramati et al published results in a 2012 issue of Nature Physics in which a new quasiparticle monopole analogue was created by exploiting a defect in Bose-Einstein condensates. This is still not a true monopole, but an analogue. However, it will help to advance the understanding of magnetism and lead to advancements in this field.