Rabi Oscillations in Gapped Bilayer Graphene

摘要

We study the nonlinear optical properties of induced gapped bilayer graphene in presence of an optical field in two different regimes namely close to resonance and far-from resonance. Resonance means when the incident optical frequency is nearly equal to the inter-band transition frequency. The Rabi frequency is obtained in both the regimes - in the resonant case it is obtained by the well known rotating wave approximation (RWA) whereas far-from resonance it is obtained using an alternative to RWA called asymptotic RWA (ARWA), introduced by us for single layer graphene. Anomalous Rabi oscillations far from resonance are attributable to the pseudospin character of monolayer graphene as well as bilayer graphene. Branching of anomalous Rabi oscillations into single and bi-harmonic modes are characteristic of bilayer graphene absent in monolayer graphene and are attributed to the quadratic energy momentum relation in the bilayer system.