Quantum Zeno-effect with polarized neutrons

Abstract

Neutron spin rotation can be achieved by proper spin rotation stages. A division into several rotation stages does not change the outcome of the rotation as long as the same interaction power acts on the quantum system. This situation changes drastically when a state separation is made behind each stage. In this case the transition between quantum states becomes hindered and a kind of quantum state freezing appears. Various unavoidable quantum loss factors caused by the parasitic effects with any interaction potential and the wave packet structure give rise to various constraints for repetitive measurements and prevents a complete freezing of a quantum state in Zeno-like experiments. Additionally, a spectral change occurs, due to the dispersive action of the interaction, which has to be taken into account when many repetitive measurements are considered. A dedicated proposal for a repetitive neutron spin rotation experiment within a perfect crystal resonator will be analyzed in detail. Unavoidable losses due to quantum phenomena can be separated from losses caused by experimental imperfections.