Controlling Kerr nonlinearity with electric fields in asymmetric double   quantum-dots
  The control of Kerr nonlinearity with electric fields in an asymmetric double quantum-dot systems coupling with tunneling is investigated theoretically. It is found that,by proper tuning of two light beams and tunneling via a bias voltage, the Kerr nonlinearity can be enhanced and varied within a wide scale. 
Yi-Wen Jiang, Ka-Di Zhu