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Q: Fachverband Quantenoptik und Photonik
Q 48: Ultracold atoms: Traps and cooling
Q 48.6: Talk
Thursday, March 21, 2013, 12:15–12:30, A 310
Electron guiding on a surface-electrode microwave chip — •Jakob Hammer1, Johannes Hoffrogge1, Dominik Ehberger1, and Peter Hommelhoff1,2 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching — 2Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen
We investigate the guiding of electrons in a miniaturized planar AC-quadrupole guide (linear Paul trap) [1]. Electrons propagating freely along electrodes on a micro-fabricated chip experience a tight transverse harmonic confinement. For our parameters the quantum mechanical ground state of the guiding potential is still resolvable by electron optics. This encourages experiments to prepare electron matter-waves in the transverse motional ground state by matching the wavefunction of an incident electron with the ground state of the microwave guide.
Here we report on our ongoing experimental efforts. We use a single-atom tip electron emitter, a point source producing an exceptionally bright and fully coherent electron beam, to inject electrons into the guide. For collimation of the emitted electron wave packet we have fabricated a micron-scale electrostatic lens. Efficient ground state coupling requires a spot size of 100 nm and an angular spread of 1 mrad of the incoming electron wavefunction. We present the current status of the experiment as well as results from numerical optimization of the electrode layout, which aims at the adiabatic injection of electrons and the design of more complex structures like beam splitting elements.
[1] J. Hoffrogge, R. Fröhlich, M. Kasevich and P. Hommelhoff , Phys. Rev. Lett. 106, 193001 (2011).