Wave-Particle Duality in N-Path Interference
  Bohr's principle of complementarity, in the context of a two-slit interference experiment, is understood as the quantitative measures of wave and particle natures following a duality relation ${\mathcal D}^2+{\mathcal V}^2 \le 1$. Here ${\mathcal D}$ is a measure of distinguishability of the two paths, and ${\mathcal V}$ is the visibility of interference. It is shown that such a relation can be formulated for $N-$slit or $N-$path interference too, with the proviso that the wave nature is characterized by a measure of {\em coherence} (${\mathcal C}$). This new relation, ${\mathcal D}^2+{\mathcal C}^2 \le 1$ is shown to be tight, and reduces to the known duality relation for the case $N=2$. A recently introduced similar relation (Bagan et al., 2016) is shown to be inadequate for the purpose. 
Tabish Qureshi (Centre for Theoretical Physics, JMI, New Delhi), Mohd   Asad Siddiqui (NIT Patna and CTP JMI, New Delhi)
quant-ph