Special Seminar: Correlation and topology in two-dimensional Co1/3-TaS2

Affiliation: Department of Physics & Astronomy, Seoul National University

 Title: Correlation and topology in two-dimensional Co1/3-TaS2

Date & Time: Tuesday, 21^st January 2025 at 4:00 p.m.

Two dimensions are always unique in physics as they are the dimensions that can be easily accessible through algebraic solutions, as beautifully demonstrated by Lars Onsager for the Ising model about 80 years ago. His model showed that magnetism offers a useful window into nature where many interesting things happen. The whole motivation behind Van der Waals magnets is just that: using real materials to study magnetism in two dimensions. It is a sure way of understanding correlation of magnetism via Coulomb U on two dimensions. A recent twist in the whole business of vdW magnets is the realization that some of them can host another interesting, more timely, physics of topology. MnBi2Te4, the first magnetic topological insulator, is a prime example. Other than that, we do not know many examples. In my talk, I will introduce another example in Co1/3-TaS2, which shows the smallest possible skyrmion phase without the need for a magnetic field. In principle, it can be exfoliated down to two dimensions and studied for the stability of the skyrmion phase.