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

Autor(en)

Stephan Sponar, Jürgen Klepp, Rudolf Loidl, Stefan Filipp, Katharina Durstberger-Rennhofer, Reinhold Bertlmann, Gerald Badurek, Helmut Rauch, Yuji Hasegawa

Abstrakt

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.

Organisation(en)

Physik Funktioneller Materialien, Teilchenphysik

Externe Organisation(en)

Technische Universität Wien, Eidgenössische Technische Hochschule Zürich

Journal

Physical Review A

Band

81

Anzahl der Seiten

10

ISSN

1050-2947

DOI

https://doi.org/10.1103/PhysRevA.81.042113

Publikationsdatum

2010

Peer-reviewed

Ja

ÖFOS 2012

103034 Teilchenphysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/geometric-phase-in-entangled-systems-a-singleneutron-interferometer-experiment(5928a9db-ff24-4975-82d5-f216682621ee).html