NanoScience Colloquium by Associate Prof. Thomas Olsen from Technical University of Denmark (DTU)

Magnetism in 2D: basic theory and high throughput calculations.

Abstract: A fundamental theorem of thermodynamics (the Mermin-Wagner theorem) implies that magnetism cannot exist in two dimensions (2D). Yet, in 2017 a monolayer of CrI3 was shown to exhibit ferromagnetic order below 45 K and since then, the field of 2D magnetism has been intensively scrutinized.  In this lecture I will outline the basic arguments of the Mermin-Wagner theorem and then discuss the fundamental loophole that have allowed researchers to bypass it. I will then present the basics of first principles and sketch how high-throughput computations may be used as a powerful tool to identify new 2D magnets.