St. Sponar, J. Klepp, R. Loidl, S. Filipp, K. Durstberger-Rennhofer, R. Bertlmann, G. Badurek, H. Rauch, Y. Hasegawa:

"Geometric phase in entangled systems: A single-neutron interferometer experiment";

Physical Review A,81(2010), S. 042113-1-10.

The influence of the geometric phase on a Bell measurement, as proposed by Bertlmann et al. [Phys. Rev. A

69, 032112 (2004)] and expressed by the Clauser-Horne-Shimony-Holt (CHSH) inequality, has been observed

for a spin-path-entangled neutron state in an interferometric setup. It is experimentally demonstrated that the

effect of geometric phase can be balanced by a change in Bell angles. The geometric phase is acquired during a

time-dependent interaction with a radiofrequency field. Two schemes, polar and azimuthal adjustment of the Bell

angles, are realized and analyzed in detail. The former scheme yields a sinusoidal oscillation of the correlation

function S, dependent on the geometric phase, such that it varies in the range between 2 and 2√2 and therefore

always exceeds the boundary value 2 between quantum mechanic and noncontextual theories. The latter scheme

results in a constant, maximal violation of the Bell-like CHSH inequality, where S remains 2√2 for all settings

of the geometric phase.

http://dx.doi.org/10.1103/PhysRevA.81.042113

http://publik.tuwien.ac.at/files/PubDat_192213.pdf

Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.