Dec 12. 2023, 09:45 — 10:30
Antiferromagnetic spin systems are magnetic lattice systems in which the exchange interaction between two spins favors anti-alignment. Such systems are said to be geometrically frustrated, if due to the geometry of the lattice no spin configuration can simultaneously minimize all pairwise interactions. As a consequence of that, ground states of frustrated spin systems may exhibit nontrivial patterns and give rise to unconventional magnetic order. An example of such a system is the antiferromagnetic XY-model on the triangular lattice (AFXY). Here the frustration leads to a concentration of energy at a surface scaling which can be tracked via the so-called chirality of the spin field. In this talk we are concerned with the discrete-to-continuum variational analysis of the AFXY in an energetic regime where the system cannot overcome the energetic barrier of a chirality transition and instead finitely many vortex-type singularities emerge in the continuum limit.
This is joint work with M. Cicalese (TU Munich), L. Kreutz (TU Munich), and G. Orlando (Politecnico Bari).