Observation of the topological Aharonov-Casher phase shift by neutron interferometry
Abstract
The phase shift predicted by Aharonov and Casher for a magnetic dipole diffracting around a charged electrode has been observed for the case of thermal neutrons, using a neutron interferometer containing a 30-kV/mm vacuum electrode system. The judicious use of the Earth's gravitational field introduces a spin-independent phase shift which enables unpolarized neutrons to be used. A supplementary magnetic bias field of the correct magnitude allows first-order sensitivity to be achieved; even so, the theoretically predicted phase shift is only 1.50 mrad for the geometry and conditions of the experiment. We observe a phase shift of 2.19+/-0.52 mrad.
- Publication:
-
Physical Review Letters
- Pub Date:
- July 1989
- DOI:
- 10.1103/PhysRevLett.63.380
- Bibcode:
- 1989PhRvL..63..380C
- Keywords:
-
- 41.70.+t;
- 03.65.-w;
- 42.50.-p;
- Quantum mechanics;
- Quantum optics