Goos—Hänchen effect in neutron optics and the reflection time of neutron waves
A.I. Frankb aLomonosov Moscow State University, Department of Physics, Leninskie Gory 1 build. 2, Moscow, 119991, Russian Federation bFrank Neutron Physics Laboratory, Joint Institute of Nuclear Research, Dubna, Moscow Region, Russian Federation
The Goos—Hänchen (GH) effect, a longitudinal shift of a wave beam at total internal reflection, is well-known in optics and has been repeatedly observed for light, micro- and ultrasonic waves. This paper considers the GH effect for a massive particle reflected from a material boundary. A close relation is shown to exist between the longitudinal shift and reflection time delay. In the case of a neutron reflected from a planar resonant system, a giant longitudinal shift of either positive or negative sign can occur, corresponding to a large reflection group delay time. This time can also be negative, which is not inconsistent with the causality principle. Prospects for the experimental observation of the GH effect and group delay time for neutron reflection are reviewed.
Keywords: neutron optics, wave beams, Goos—Hänchen effect, group delay time, reflection from multilayer structures PACS:03.65.Nk, 03.75.Be, 41.85.−p, 42.25.Fx, 78.70.−g (all) DOI:10.3367/UFNe.2017.11.038235 URL: https://ufn.ru/en/articles/2018/10/b/ Citation: Bushuev V A, Frank A I "Goos—Hänchen effect in neutron optics and the reflection time of neutron waves" Phys. Usp.61 952–964 (2018)