High precision measurement of the topological Aharonov-Casher effect with neutrons

The phase shift predicted by Aharonov and Casher (AC) for a magnetic dipole diffracting around a line charge was first observed by Cimmino et al. usin g a neutron interferometer. A number of subsequent atom interferometry expe riments have been performed to observe this effect. These experiments measu red the v x E phase shift due to the magnetic field induced in the rest fra me of the atom, with no indication of the topological nature of the AC inte raction. We intend to perform a high precision AC experiment with neutrons to improve the accuracy of our previous results and to highlight the topolo gical nature of the effect. Finally, we present a novel geometry to achieve a spin-dependent magnetic phase shift. (C) 2000 Elsevier Science B.V. All rights reserved.