Date/Time
Date(s) - 14/02/2024
3:30 pm - 4:30 pm

Location
Physics and Astronomy Department

ABB 102

Dr. Erik Sorensen
Professor, McMaster University
https://physics.mcmaster.ca/~sorensen/

Title: Directions in Magnetism

Abstract: 

The Ising model is familiar to many of us from a course in statistical mechanics, along with its solution by Ernst Ising in 1924. However, if the type of Ising interaction varies with the bond direction, a surprisingly complex behavior arises. In particular, the bond-directional Ising interactions present in the Kitaev model has recently attracted considerable attention. The attention has mostly focused on the two-dimensional honeycomb lattice version of the Kitaev model, where several materials have been identified as potential realizations. However, one can also imagine realizing simpler one-dimensional Kitaev spin chains that still has a surprisingly rich structure. One example is the ferromagnetic material CoNb2O6 which shows signatures of bond directional interactions. It is usually assumed that for Kitaev spin chains, the presence of a magnetic field does not lead to any interesting new physics.

However, for an in-plane field this is not true, and an unusual chiral soliton phase in the antiferromagnetic Kitaev chain. In this talk, I will present some of the interesting phases that can be identified in chains, planes and ladders of materials with bond-directional interactions, and discuss some of the techniques we use to study them.