Enhanced Kerr nonlinearity with nonlinear amplification based biexciton coherence Seyyed Hossein Asadpour and H. Rahimpour Soleimani Eur. Phys. J. Plus, 130 1 (2015) 18 Published online: 30 January 2015 DOI: 10.1140/epjp/i2015-15018-4