Enhanced index without absorption in a semiconductor quantum-dot nanostructure

•High refractive index without absorption in a solid is investigated.•Our system is much more practical than the atomic counterpart.•The refractive index can be easily controlled via corresponding parameters.

We investigate the absorptive–dispersive properties of a weak field in a coupled semiconductor double-quantum-dot nanostructure. It is found that the enhanced index of refraction without absorption can be easily controlled via adjusting properly the corresponding parameters of the system. Our scheme opens the possibility to control index of refraction without absorption in a coupled semiconductor double-quantum-dot nanostructure.