Observation of anomalous transmission bands for neutron waves in a multibilayer film

Abstract
The authors report observation of a neutron wave phenomenon complementary to Bragg reflection: A synthetic multibilayer 'crystal' was found to be transparent within a region of energy lying below the potential barrier established by one of the constituent film materials. The observed transmission band is characterised by wave tunnelling through an arbitrary number of potential barriers of-in principle-infinite total width. This phenomenon occurs in conditions of wave resonance in the coupled resonator potential established by the multibilayer system.