Seminar

Topological systems - both in equilibrium and driven out of equilibrium - have been a popular topic of research for the last several years. In this talk, I am going to use the Bernevig - Hughes -Zhang model - one of the earliest known two - dimensional topological insulators - as an example to show how one can generate and/or manipulate topological phases using an external perturbation that is periodic in time. In particular, I will be discussing how using an elliptically polarized light can generate phases with topological invariants different from the equilibrium system. Moreover, the phases can be manipulated by varying the polarization of incident light. I will also briefly discuss how one can generate higher - order topological phases using periodic driving which results in states localized at the corners of a two-dimensional system.

References:
[1] R. Seshadri, D. Sen, arXiv:2206.03473

[2] R. Seshadri, A. Dutta, D. Sen, Phys Rev B 100, 115403