Young Double Slit Experiment

Diffraction pattern emerged even for single particle at a time rather than an expected blur from a classcial result.

$I=|E(\overrightarrow{r}){|}^2=|E_1^0{|}^2+|E_2^0{|}^2+2E_1^0{E}_2^0\cos \delta$.

Probability amplitudes of the wave from the source (Either $\gamma$ or $e^{-}$).