  The paper demonstrates that negative refractive index can be achieved via
tuning the tunneling rate between a double quantum dots(QDs) system by applying
a bias voltage, and a pulsed laser. As the bias voltage being changed, the
refraction index can be tunable to negative with the simultaneous negative
permittivity and permeability. While the varying pulsed laser is applied to the
double QDs system, moreover, the negative refractive index with little loss can
be obtained. The flexible manipulation on a solid state system to realize
negative refraction may give a new way for experimental research in the future.
