Frankfurt 2006 – scientific programme

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MO: Molekülphysik

MO 57: Poster: Cold Molecules

MO 57.4: Poster

Thursday, March 16, 2006, 16:30–18:30, Labsaal

A microdecelerator for polar molecules — •Samuel A. Meek, Hendrick L. Bethlem, Horst Conrad, and Gerard Meijer — Fritz-Haber-Institut der MPG, Faradayweg 4-6, 14195 Berlin

By utilizing the forces that polar molecules experience in inhomogeneous electric fields, a variety of molecular-optical elements have been experimentally demonstrated. The electrode dimensions used for previous experiments have been relatively large. To reach sufficiently high electric fields with electrodes which are several mm apart, potentials of tens of kV need to be applied. We have recently demonstrated that modest voltage differences applied to µm-sized electrodes produce equally high electric fields [1]. Here, we present design and trajectory calculations for an electrostatic decelerating and trapping device consisting of a periodic array of 1000 microstructured linear electrodes deposited on a planar insulating substrate. Alternating electric potentials are applied to the electrodes in such a way that local electric field minima occur above the electrode plane. Application of harmonic waveforms to periodic groups of 6 electrodes allows us to steer the resulting periodic minima along the array in a continuous manner without changing their distance above the electrodes. Deceleration is achieved by linearly reducing the frequency of the applied waveforms. The molecule of choice for these experiments is a³Π₁ CO. Since the lifetime of this metastable state is about 3 ms, the molecules can be detected via their spontaneous emission. Trajectories covering a whole range of initial conditions in phase space have been calculated to estimate the stable region during deceleration.

[1] S.A. Schulz et al, Phys.Rev.Lett. 93, 020406 (2004)