ICMT Seminar: "Higher multipole moments in crystalline insulators"


Wladimir Benalcazar, Univeristy of Illinois at Urbana Champaign

Date Mon, 03/12/2018

190 ESB

Time 12:00 pm

Institute for Condensed Matter Physics

Event Type Seminar/Symposium

It is known that crystalline insulators can host electric dipole moments. However, whether higher electric multipole moments can arise in them has been an open question. In this talk, I will discuss the existence of higher multipole moments in crystalline insulators. I will show minimal models for which the quadrupole and octupole moments are topologically quantized electromagnetic observables and will describe experimental implementations of the quadrupole lattice that have been recently tested in a number of metamaterials. I will also discuss electronic pumping phenomena associated with these higher moments, making a natural connection with a new class of topological insulators: "higher-order topological insulators", which have recently been found.