NONCOMMUTATION OF PAULI SPIN OPERATORS IN NEUTRON POLARIMETRY

Abstract A neutron spin polarimetric experiment is described which explicitly demonstrates the noncommutation properties of Pauli spin operators. Commutation of the sequential order of two successive π spin rotators leads to different final polarization states of the transmitted neutron beam. An interpretation of the observations is also given in terms of interference between two mutually orthogonal spin states that undergo different phase shifts upon the commutation of spin rotators.