The effective role of Dirac mass in nonlinear optical spectra of silicene

Abstract

Silicene is a monolayer honeycomb system made of silicon. It is a two-dimensional topological insulator that undergoes a topological phase transition to a band insulator by applying an external electromagnetic field. All topological phase transitions in silicene come by tuning of its Dirac mass. In this paper, the tuning of the Dirac mass of silicene has been done by the application of Floquet theory. The nature of the Dirac mass in a Bloch–Seigert shift is shown in topological trivial and non-trivial phases of silicene. The collapse-revival spectra have been described by Floquet theory in silicene. The differential transmission coefficient of pump–probe spectra is shown, which have the capability of distinguishing Floquet theory oscillations in topological trivial and non-trivial phases of silicene. All these results are also valid for germanene and stanene by changing the material parameters.