LAUSR

Abstract The pseudorelativistic behaviour of carriers is found in the energy bands of certain class of two dimensional (2D) semi-conducting materials such as phosphorene. In this article, the nonlinear optical response of pseudorelativistic electrons in phosphorene under intense applied electromagnetic field is investigated. Using Floquet theory, we demonstrate the anisotropic behaviour of anomalous Rabi oscillations in phosphorene, which occurs far from the conventional resonance. The role of anisotropy on anomalous Rabi oscillations in phosphorene is also justified numerically. The Bloch-Siegert shift is observed under strong driving field that strongly depends on the anisotropy of the energy bands of phosphorene. A theoretical description of the pump-probe experiment is given to detect the anomalous Rabi oscillations in phosphorene. The differential transmission coefficient shows a sinusoidal behaviour as a function of pump pulse duration whose amplitude exhibits a power law decay, which is quite different from graphene (relativistic fermionic system). So the Floquet theory can be used to characterize the different fermionic systems.