Upcoming lecture of the Szilárd Leó Colloquium of the BME Institute of Physics:
The soliton phenomenon was first described in 1834 by John Scott Russell who observed a wave in the Union Canal in Scotland that preserves its shape while propagating freely, at constant velocity, and recovers it even after collisions with other such localized wave packets. 1961 Tony Skyrme identified topologically stable three-dimensional configurations in a pion field as baryons. Nowadays we find a lot of similar phenomena in magnetic textures, but not only in one dimension as in domain walls or in the Union Canal, respectively, but also in two and three dimensions known as skyrmions and hopfions, respectively. Actually, we have now a zoo of particles predicted and also observed using a spectrum of experimental techniques such as spin-polarized scanning tunneling microscopy, Lorentz microscopy, electron microscopy with off-axis holography, or x-ray scattering. In this colloquium, I will introduce these particles, their topological nature, give arguments of their stability, discuss their lifetime, dynamics, their transport properties, and their potential field of applications. I relate their stability to underlying microscopic interactions and look at promising materials realizations by applying a multiscale simulation approach combining first-principles calculations with atomistic simulations.