Effect of gate voltage on Kerr nonlinearity in a dielectric slab doped with InAs/GaAs double-quantum-dot molecules

The study examines the linear absorption and third-order nonlinear dispersion properties of a dielectric slab doped with asymmetric InAs/GaAs double-quantum-dot molecules interacting with a low-intensity laser field. Unlike other studies, this research utilizes a gate voltage to induce tunneling-induced transparency to enhance Kerr nonlinearity. The study presents the optimal conditions for achieving Kerr nonlinearity enhancement and demonstrates that interdot electron tunneling increases the group index, leading to subluminal light propagation. Furthermore, the study shows that a dielectric slab with high electric permittivity is the most effective choice for achieving absorption-free, large Kerr nonlinearity.