Neutron whispering gallery

Helmut Rauch

Go Ichikawa, K. Mishima

A neutron whispering gallery state is a quantum state localized on a material surface bound by the centrifugal force and the material potential. Precise measurements of such quantum states enable tests of quantum mechanics in noninertial frames, characterization of the surface potential, and searches for hypothetical short-range interactions at the nanometer scale. We observed a neutron whispering gallery state on a SiO 2 concave mirror using a pulsed cold neutron beam. The measured results agree with theoretical calculations within 1.9% for the centrifugal acceleration a ≈ 7 × 10 7 m / s 2 , which is due to unmodeled deviations of the shape of the concave mirror edge from an ideal one. We found that the sensitivity itself was 1 × 10 − 4 , which is two orders of magnitude better than the above agreement.

V. K. Ignatovich

V. K. Ignatovich

Alexei Yu. Voronin, Валерий Викторович Несвижевский, Serge Reynaud

We theoretically study the interference of the long-living quasi-stationary quantum states of antihydrogen atoms, localized near a concave material surface. Such states are an antimatter analogue of the whispering gallery states of neutrons and matter atoms, and similar to the whispering gallery modes of sound and electro-magnetic waves. Quantum states of antihydrogen are formed by the combined effect of quantum reflection from the van der Waals/Casimir–Polder (vdW/CP) potential of the surface and the centrifugal potential. We point out a method for precision studies of quantum reflection of anti-atoms from vdW/CP potential; this method uses the interference of the whispering gallery states of antihydrogen.

Alexei Yu. Voronin, Валерий Викторович Несвижевский, Serge Reynaud

We predict the existence of antihydrogen atom long-living quasistationary states, localized near a curved material surface due to quantum reflection from the van der Waals--Casimir potential. Such states are an atom-wave analog of the whispering-gallery (WG) modes, known in acoustics, optics, and neutron physics. We argue that the WG states of antihydrogen atoms could be regarded as a close analog of recently predicted gravitational states of antihydrogen where the centrifugal potential plays the role of the linear gravitational potential. We point out a method for the precision measurement of anti-atom-matter interactions, based on the study of interference of WG antihydrogen states.