Topological edge conduction induced by strong anisotropic exchange interactions

Here, we predict that an interplay between isotropic and anisotropic exchange interactions in a honeycomb lattice structure can lead to topological edge conduction when the anisotropic interaction is at least twice the strength of the isotropic interaction. For materials like Na₂⁢IrO₃, such a strong anisotropic exchange interaction simultaneously induces a zigzag type of antiferromagnetic order that breaks the time-reversal symmetry of the topological edge conductor. We show that the electronic transport in such topological conductors will exhibit a quantized Hall conductance without any external magnetic field when the Fermi energy lies within a particular energy range.. Authors: Sayed, Shehrin [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); University of California, Berkeley, CA (United States); TDK Headway Technologies, Inc., Milpitas, CA (United States)] (ORCID:0000000179634003); Brahma, Pratik [University of California, Berkeley, CA (United States)]; Hsu, Cheng-Hsiang [University of California, Berkeley, CA (United States)]; Salahuddin, Sayeef [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); University of California, Berkeley, CA (United States)]. DOE Contract: AC02-05CH11231. Subjects: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; exchange interaction; magnetic order; quantum Hall effect; quantum transport; spintronics; topological materials; topological phase transition