$T^3$-interferometer for atoms
  The quantum mechanical propagator of a massive particle in a linear gravitational potential derived already in 1927 by Earle H. Kennard \cite{Kennard,Kennard2} contains a phase that scales with the third power of the time $T$ during which the particle experiences the corresponding force. Since in conventional atom interferometers the internal atomic states are all exposed to the same acceleration $a$, this $T^3$-phase cancels out and the interferometer phase scales as $T^2$. In contrast, by applying an external magnetic field we prepare two different accelerations $a_1$ and $a_2$ for two internal states of the atom, which translate themselves into two different cubic phases and the resulting interferometer phase scales as $T^3$. We present the theoretical background for, and summarize our progress towards experimentally realizing such a novel atom interferometer. 
M. Zimmermann, M.A. Efremov, A. Roura, W.P. Schleich, S.A. DeSavage,   J.P. Davis, A. Srinivasan, F.A. Narducci, S.A. Werner...
quant-ph physics.atom-ph