Quantum Matters Seminar: Igor Mazin

Fluctuation-driven Phenomena in the Kagome-net Magnets REMn6Sn6

Igor Mazin
George Mason University

Wednesday, April 16, 2025
2:00 p.m.

In-person: QNC 1201

Abstract: I will discuss four different nontrivial manifestations of spin fluctuations in 166 materials:

1. Mn spin fluctuation in Y166 and Er166 generate (at finite temperature) topological Hall effect, prohibited by symmetry at the static level.
2. Tb spin fluctuations in TbMn6Sn6 trigger a spontaneous spin-reorientation transition.
3. Er spin fluctuations trigger a ferrimagnet-spiral transition in ErMn6Sn6.
4. RE and Mn spin fluctuations dramatically modify the conventional scaling of the anomalous Hall effect.

This shows that spin fluctuations can have qualitatively diverse and nontrivial effects already on the mean field level, i.e. outside of the 
standard framework of suppressing the long-range order and triggering order from disorder transitions.