Multiple-Fano-resonance-induced fast and slow light in the hybrid nanomechanical-resonator system

We investigate the multiple-Fano-resonance-induced fast and slow light in a hybrid nanomechanical-resonator (NR) system, where a doubly clamped suspended NR with an embedded quantum dot driven by two-tone fields is coupled to another two NRs with different frequencies via the Coulomb interaction. We display the absorption spectra of the weak probe field under different exciton-pump field detuning, and the sharp peaks in the absorption spectra are determined by the interaction between the NRs under the resonance. In the off-resonance, the absorption spectra can exhibit multiple Fano resonance, and the positions of the multiple Fano resonances are related to the interaction between the NRs and the frequencies of the different NRs. Furthermore, the multiple Fano resonances are accompanied by the rapid normal phase dispersion, which indicates the slow- and fast-light effect. We obtain that the group velocity index is tunable by the interaction between the NRs and the detuning, which can reach the conversion between the fast and slow light.