| Description: | [DPS Seminar] Dr. Priyanka Mohan (HRI Allahabad) -- Floquet topological transitions in spin-orbit coupled materials: A B-W approach |
| Date: | Thursday, Sep 21, 2017 |
| Time: | noon - 1 p.m. |
| Venue: | 113, DPS Meeting Room, RC |
| Details: | We study photo-induced topological transitions in 2D materials with spin-orbit coupling. The examples for such materials are silicene, germanene and stanene etc where the Hamiltonian is Dirac 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. |
| Calendar: | Seminar Calendar (entered by anandamohan) |