Shining light on SO coupling: A B-W approach

TKM Institutsseminar

Speaker:

Dr. Priyanka Mohan

Date:

24/03/2017 12:30

Where:

Room 11.12, 11th Floor, Bldg. 30.23, Campus South

Affiliation:

Harish-Chandra Research Institute - Allahabad, INDIA

Host:

Igor Gornyi, TKM

Abstract

We study photo-induced topological transitions in 2D materials with spin-orbit coupling. The examples for such materials are silicene, germanene and stanene which are graphene like and driven periodically by an incident laser. The system is studied in a high-frequency limit using expansion based on the Brillouin-Wigner perturbation theory. The effective Hamiltonian thus computed has new terms renormalizing the bare Hamiltonian as well as new longer ranged couplings. We calculated the phase diagram using the effective Hamiltonian and compared with that of direct numerical computations. It is found that at high enough frequencies, the high energy expansion gives accurate results.