title: Nonclassical paths in quantum interference experiments.
abstract: In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well-known text books in quantum mechanics implicitly and/or explicitly use this assumption that is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from nonclassical paths in quantum interference experiments that provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these nonclassical paths is difficult to present. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore 560 080, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Sawant
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore 560 080, India.
authors.forename: Joseph
authors.initials: J
authors.lastname: Samuel
authors.affiliation: Centre for High Energy Physics, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Aninda
authors.initials: A
authors.lastname: Sinha
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore 560 080, India.
authors.forename: Supurna
authors.initials: S
authors.lastname: Sinha
authors.affiliation: Raman Research Institute, Sadashivanagar, Bangalore 560 080, India and Institute for Quantum Computing, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Urbasi
authors.initials: U
authors.lastname: Sinha