Observation of quasibound states of neutron in Fabry-Perot magnetic thin-film resonator using Larmor precession

Abstract Authors have measured Larmor precession angles of neutron spin transmitted through magnetized permalloy45(PA)-germanium(Ge)-PA and PAGePAGePA Fabry-Perot magnetic thin-film resonators at various incident angles above and below the critical angle of total reflection. The Larmor precession angles due to the Fabry-Perot resonator show sinusoidal oscillation as a function of the incident angles, which corresponds to quasibond states of the Fabry-Perot resonator for ↑ spin. The oscillation is well reproduced by the theoretical phase difference of ↑ and ↓ spin neutron wave functions based on one-dimensional Schrodinger equation.