Spin texture of an irradiated warped topological insulator surface

The Institute of Mathematical Sciences, C.I.T. Campus - Chennai 600 113, India and TIFR Centre for Interdisciplinary Sciences - Hyderabad 500075, India

Received: 16 May 2016
Accepted: 8 August 2016

Abstract

Topological insulator is a new state of matter which exhibits exotic surface electronic properties. Determining the spin texture of this class of materials is of paramount importance for understanding its topological order and can lead to potential applications in spintronics. Here, we have investigated the nature of the surface state of the topological insulator with hexagonal warping subjected to an off-resonant circularly polarized light. The resulting electronic ground state exhibits a novel feature of spin texture breaking the conventional spin-momentum locking present on a topological insulator surface. The observed spin texture is shown to be a consequence of the symmetry group of the underlying crystal. The generalisation of our method to the other 2D graphene-like systems is straightforward. Our calculation traces a simple experimental route for a realisation of the non trivial spin textures.