Theoretical Physics Colloquium

Exotic orders from multispin interactions: From heavy fermions to chiral spin liquids

by Prof. Arun Paramekanti (University of Toronto, Canada)

Tuesday, September 11, 2018 from to (Asia/Kolkata)
at AG 69
Upon approaching a Mott transition from the insulating side, fermions get progressively more delocalized resulting in higher order spin interactions (e.g., 3-spin and 4-spin exchange) becoming more important. This has been proposed as a driver for novel magnetic orders in solid Helium-3, and spin liquid behavior in quasi-2D organic materials as well as Helium-3 on graphite. I will discuss analogues of such physics in two new settings –  Heavy fermion materials near the small-to-large Fermi surface transition, and Mott insulators formed from correlation effects in topological bands. For the heavy fermion materials, I will discuss how multispin interactions could lead to quadrupolar and coexisting octupolar orders. For the topological Mott insulators I will discuss how chiral spin liquids emerge from non-coplanar spin crystals.