ProjectEntwicklung eines Quanten-Elektronenmikroskops: Bestimmung der Dekohärenz-Zeiten und Entwicklung kohärenter…

Basic data

Entwicklung eines Quanten-Elektronenmikroskops: Bestimmung der Dekohärenz-Zeiten und Entwicklung kohärenter Strahlaufspaltungs-Methoden für elektronische Überlagerungszustände
11/1/2016 to 1/31/2017
Abstract / short description:
Several novel techniques in the last decade enable a precise spatial and temporal control over the coherent electron matter wave in free space. One of the resulting technical innovations is the recently proposed quantum electron microscope. It is currently developed in the research group of Prof. Mark Kasevich at Stanford University, USA. The device relies on an interaction-free, non-destructive measurement principle. It has the potential advantage towards existing electron microscopes to scan probes with significantly less electron deposition, allowing the investigation of e.g. fragile biomolecules. All proposed realization schemes require a large coherent electron beam path separation and a long decoherence time of an electronic superposition state in an electromagnetic trap. This time is limited by Coulomb-interaction with the trap-electrodes giving which-path information to the environment. The research group of Dr. Alexander Stibor in Tübingen is studying in a current DFG-project Coulomb-induced decoherence mechanisms in a biprism electron interferometer. The setup will allow the measurement of decoherence times for quantum states of superposed free electrons in the vicinity of metallic, semiconducting and superconducting surfaces at various temperatures. Thereby, the distance between the electrons and the conducting environment as well as the beam path separation can be varied and the resulting decoherence can be compared to theoretical models. Additionally, the group plans to modify an existing experimental setup to test selected schemes for a maximization of the coherent beam path separation based on recently published simulations. Considering the strong overlap of research topics between these two groups, the Physics Department at Stanford University invited Dr. Stibor to be a visiting scholar for three month. This application requests the financing of this research stay. Thereby the experiments in both groups should be coordinated to measure and optimize in Tübingen the parameter range relevant for the current microscope design in Stanford. This concerns the conductivity and temperature of the decoherence surface, the beam path separation and the electron emission energy. The distinct experience of the group in Tübingen with novel single atom tip electron sources and the reduction of dephasing related to a noisy environment should also be introduced to the experiments in Stanford. The purpose of the research stay is to exchange and probe ideas and to initiate a collaboration project for the development of optimized beam guiding techniques for the quantum electron microscope.
matter waves
electron microscopy

Involved staff


Institute of Physics (PIT)
Department of Physics, Faculty of Science

Local organizational units

Institute of Physics (PIT)
Department of Physics
Faculty of Science


Bonn, Nordrhein-Westfalen, Germany

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