Tunneling induced transparency and giant Kerr nonlinearity in multiple quantum dot molecules

• The analytic expression for linear and nonlinear susceptibility is obtained.
• The multiple tunneling couplings can induce multiple transparency windows.
• Different probe fields can acquire giant Kerr nonlinearity simultaneously.
• The giant Kerr nonlinearity can be combined with vanishing absorption.

The linear absorption and the Kerr nonlinearity of multiple quantum dots molecules controlled by the tunneling rather than the laser fields are investigated. The tunneling between the dots can induce multiple transparency windows. By varying the energy splitting of the excited states and the tunneling intensity, the width of the tunneling induced transparency windows can be narrowed. Within the narrowed transparency windows, the steep dispersion profile of the probe field makes it possible to enhance the Kerr nonlinearity. Therefore more than one probe fields with different frequencies can acquire giant Kerr accompanied by vanishing absorption simultaneously.