Testing Quantum Mechanics using a Triple slit experiment

As one of the postulates of quantum mechanics, Born's rule tells us how to get probabilities for experimental outcomes from the complex wavefunction of the system. It's quadratic nature entails that interference occurs in pairs of paths. An experiment is in progress in our laboratory that sets out to test the correctness of Born's rule by testing for the presence or absence of genuine three-path interference [1]. This is done using single photons and a three slit aperture. Although the Born rule has been indirectly verified to high accuracy in other experiments, the consequences of a detection of even a small three-way interference in the Quantum mechanical null prediction are tremendous. If a non-zero result were to be obtained, it would mean that Quantum Mechanics is only approximate, in the same way that the double slit experiment proves that classical physics is only an approximation to the true law of nature. This would give us an important hint on how to generalize Quantum Mechanics and open a new window to the world. Some preliminary observations have been reported in reference [2]. In this talk, I will show results that bound the possible violation of the second sum rule and will point out ways to obtain a tighter experimental bound. [1] R. D. Sorkin, Mod. Phys. Lett. A 9, 3119 (1994). [2] U. Sinha et al, in Foundations of Probability and Physics-5, A I P Conference Proceedings, Vol. 1101, pp. 200-207, New-York (2009)