November 28, 2016
Published by Stephan Sponar
In general a quantum system’s state vector carries *phase* information, a non-physical property that cannot be measured in an intensity measurement. However, a phase difference between states vectors is a physical quantity, giving rise to the phenomenon of *interference*. Phase accumulation is, at first sight, a consequence of dynamics of the state evolutions. In addition to and independent of this dynamical phase M. V. Berry discovered in the beginning of the eighties of the last century a phase due to the **geometrical** origin of the state evolution independent of its dynamical properties.

October 16, 2016
Published by Stephan Sponar
Influence of *rotation* on the **phase** of light passing through an optical interferometer has been theortically investigated over a century. The **Sagnac effect** predicted the observation of a phase shift proportional to the scalar product of the *rotation frequency* and the area of the *interferometer*. In 1988 B. Mashhoon predicted a new relativistic quantum mechanical effect, i.e., a coupling of *spin* with the angular velocity of a *rotating* reference system. Following the prediction, the spin-rotation interaction has been successfully derived from the Dirac theory, a concrete measurement however is still missing. The first proposal in this regard in- cluded a measurement via neutron-interferometry.