A neutron interferometric measurement of a phase shift induced by Laue transmission.

The phenomenon of a neutron phase shift due to Laue transmission in a perfect crystal blade is discussed. Quantitative measurements of this phase shift are presented in the vicinity of the Bragg condition well in agreement with numerical calculations. The phase shift shows a strong angular sensitivity and might constitute an interesting opportunity for precision measurements of fundamental quantities like the neutron-electron scattering length or gravitational short-range interactions.