A neutron interferometer experiment that Quantum Mechanics cannot explain

Yuji Hasegawa, Rudolf Loidl, Matthias Baron +2 more

G. Badurek

Yuji Hasegawa

Fundamental phenomena in quantum mechanics are investigated by the use of matter-wave optics: in the studies neutron polarimeter and interferometer are exploited. Successive measurements of 1/2-spin of the neutron are carried out to test the error-disturbance uncertainty relation. The experimental results confirm the violation of Heisenberg's original reciprocal relation for measurement error and disturbance, and the validity of the reformulated generally valid relation. In addition, as an example of a counterfactual phenomenon of quantum mechanics, interferometric experiment is performed to observe the so-called quantum Cheshire-Cat: a particle and its magnetic moment travel through the interferometer along different beam paths. The results of our experiment suggest that, with suitable pre- and post-selections, neutrons travel along one of the arms of the interferometer, while their spin is located in the other arm.

Helmut Rauch

B. Heacock, M. Arif, Robert W. Haun +3 more

Dynamical diffraction leads to an interesting, unavoidable set of interference effects for neutron interferometers. This experiment studies the interference signal from two and three successive Bragg diffractions in the Laue geometry. We find that intrinsic Bragg-plane misalignment in monolithic, "perfect" silicon neutron interferometers is relevant between successive diffracting crystals, as well as within the Borrmann fan for typical interferometer geometries. We show that the dynamical phase correction employed in the Colella, Overhauser, and Werner gravitationally induced quantum interference experiments is attenuated by slight, intrinsic misalignments between diffracting crystals, potentially explaining the long-standing 1% discrepancy between theory and experiment. This systematic may also impact precision measurements of the silicon structure factor, affecting previous and future measurements of the Debye-Waller factor and neutron-electron scattering length as well as potential fifth-force searches. For the interferometers used in this experiment, Bragg planes of different diffracting crystals were found to be misaligned by 10 to 40 nrad.

Yan Wang

So far,the neutron diffraction have been approved in many experiments,and these experiments have been explained by different theories.In order to explain neutron single-slit diffraction more exactly,we apply a quantum mechanical approach to explain the neutron single-slit diffraction,and the calculation results are good agreement with experiment data.