Biprism ion-interferometry with charged atoms and molecules for the measurement of the Aharonov-Bohm effects for particles with inner structure

• Applicant: Dr. Alexander Stibor
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 177931739

Experiments with matter-waves of coherent, free electrons are currently an expanding field of research. This is motivated by numerous technological innovations concerning the beam source, the beam manipulation and the detection. The aim of this Emmy Noether-project is the application of interferometry with electrons and ions in context to Aharonov-Bohm physics, sensor technology and decoherence. For that reason a biprism-interferometer for helium and hydrogen will be realized. A coherent and intensive single-atom tip beam source was implemented for the first time in a biprism-interferometer, where the origin of the emission is only a single atom. Furthermore a method was developed to reduce the influence of dephasing perturbations, such as mechanical and electromagnetic oscillations or temperature drifts, by a correlation analysis of the spatial and temporal particle coordinates obtained by the detector. In the course of the previous Emmy Noether-project numerous technical challenges have been solved to enable the measurement of ion-interferences during the year of extension. An ion-interferometer in principle allows for the first direct verification of the electric Aharonov-Bohm effect. Detailed simulations indicate that it is necessary to separate the beam path in the interferometer coherently by 100 µm with three biprisms. The necessary components are already manufactured and will be implemented within the year of extension. In a further experimental setup the decoherence of an electronic superposition state by Coulomb-interaction near a metallic surface in dependence of its temperature will be studied and compared to current decoherence theories. The determined decoherence time has important technical applications, for instance in the realization of a quantum electron microscope.

• DFG Programme: Independent Junior Research Groups