The cold neutron multilayer phase-spin echo interference experiment with mechanical alloying samples to investigate the state transition which derives decoherence

It has not been solved theoretically and experimentally how to explain the process which derives decoherence from coherent state though certain intera ctions between a quantum system such as a neutron and mesoscopic system, wh ich consists of many particles. It is still an open question how to explica te decoherence and the quantum process through the quantum mechanical measu rement process. In the last few decades this subject has become more import ant and discussed in various fields. Many quantum mechanical measurement th eories derive decoherence from coherent state without experimental verifica tion. Theoretically, it seems already clear that a kind of fluctuation of t he mesoscopic system derives decoherence. We have done interference experim ents to study this phenomena using spin interferometer for cold neutron ins erting such a machanical alloying (MA) samples as Ni25T75 Of different allo ying time. We chose such samples as Ni and Ti so that the total potential b ecomes zero but the fluctuation of weighted structure factor remains. We st udy this system to find the phenomena decreasing the coherence of wave func tion after once it improves in a diffuse scattering component. (C) 2000 Els evier Science B.V. All rights reserved.