SWC Seminar - Topology in Magnets: From classical spin crystals to novel quantum liquids | Shull Wollan Center

ABSTRACT

Skyrmions are spatially localized topological entities which were proposed in particle physics, and have condensed matter analogues which were discovered in quantum Hall systems and magnetic solids. Skyrmions have also been proposed as possible degrees of freedom in which one might stably store information. What happens when we have a strongly interacting system of many skyrmions?  In the first part of this talk, I will discuss some of our recent theoretical work on classical skyrmion crystals -- periodic topological spin textures -- in magnetic solids. In particular, I will focus on how skyrmion crystals are impacted by a magnetic field and how they in turn impact the motion of electrons. This will connect with ongoing experimental efforts to explore such phases and their topological Hall effect. In the second part, I will turn to the issue of how quantum fluctuations might melt such classical orders. Based on computational studies of model Hamiltonians which are of interest in condensed matter settings, I will argue that one physically reasonable outcome of the melting of skyrmion crystals might be the emergence of chiral quantum spin liquids. Finally, as a cautionary tale in the search for quantum spin liquids, I will discuss certain spinel compounds where the apparently observed `spin liquid’ behavior and absence of magnetic ordering may be understood as arising from a non-magnetic spin-orbit entangled ground state at each site.

Contact: Cristian Batista, cbatist2@utk.edu

Date: 

Wednesday, May 8, 2019 - 14:30 to 15:30

Speaker Name: 

Arun Paramekanti, University of Toronto

Location: 

Shull Wollan Center (ORNL Bldg. 8630), Room A202

Host: 

Cristian Batista

Event Type: