| January 09, 14:30
Correlations and Topology in multi-orbital models
Electronic correlations have long been known to fundamentally affect a
material's property. I will discuss situations, where they can induce topologically
nontrivial electronic states. Interaction between itinerant carriers and localized
spins on frustrated lattices can stabilize phases that are in many respects similar
to a Landau level, as a non-coplanar spin background gives the electrons a
complex phase analogous to that induced by a magnetic field. If the bands are
nearly flat, longer-range Coulomb repulsion can then induce states that are like
lattice-analogs of fractional Quantum-Hall states, but do not require an external
magnetic field.
I will also discuss Mott insulators with spin-orbit coupling, where excitations then
have combined spin and orbital character. We have investigated effective
classical spin model for spin-orbit coupled Mott insulators. The ground state has
turned out to support a vortex lattice of topological defects, Z2 vortices, whose
density is determined by the strength of the spin-orbit coupling.
IFW Dresden
Seminarraum des II. Physikalischen Instituts
Contact: not specified