Competition of trivial and topological phases in patterned graphene based heterostructures

Zoltán Tajkov, László Oroszlány, József Cserti, János Koltai

Published 2019-12-12Version 1

We explore the impact of mechanical strain on the competition of topological and trivial gap generation mechanisms in patterned graphene based heterostructures. We focus on Kekul\'e-O type distortion favoring a trivial phase and commensurate Kane-Mele type spin-orbit coupling germinating a topological phase. We derive a simple low-energy Dirac Hamiltonian incorporating the two gap promoting effects and include terms corresponding to uniaxial strain. The derived effective model explains previous ab initio results elucidating a simple physical picture. We show that while the trivial gap is sensitive to mechanical distortions the topological gap stays resilient.