Revisiting Bohr's principle of complementarity using a quantum device
  Bohr's principle of complementarity lies at the central place of quantum mechanics, according to which the light is chosen to behave as a wave or particles, depending on some exclusive detecting devices. Later, intermediate cases are found, but the total information of the wave-like and particle-like behaviors are limited by some inequalities. One of them is Englert-Greenberger (EG) duality relation. This relation has been demonstrated by many experiments with the classical detecting devices. Here by introducing a quantum detecting device into the experiment, we find the limit of the duality relation is exceeded due to the interference between the photon's wave and particle properties. However, our further results show that this experiment still obey a generalized EG duality relation. The introducing of the quantum device causes the new phenomenon, provides an generalization of the complementarity principle, and opens new insights into our understanding of quantum mechanics. 
Jian-Shun Tang and Yu-Long Li and Chuan-Feng Li and Guang-Can Guo
quant-ph