Nonlinear optical properties in a nanoring: Quantum size and   Aharonov-Bohm effect
  We have performed calculations of nonlinear optical absorption and nonlinear optical rectification of an exciton in a nanoring in the presence of the magnetic flux. Our results show that one can control properties of nonlinear optical absorption and nonlinear optical rectification of a nanoring by tuning outer and inner radius. In addition, we also find that nonlinear optical properties of a nanoring can be modulated by the magnetic flux through nanoring. 
Shijun Liang, Wenfang Xie, H. A. Sarkisyan, A. V. Meliksetyan, Huaya   Shen
cond-mat.mes-hall