Dresden 2011 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 57: Poster 3: Quantengase, Ultrakalte Atome, Ultrakalte Moleküle, Materiewellen Optik, Präzisionsmessungen, Metrologie

Q 57.102: Poster

Thursday, March 17, 2011, 16:30–19:30, P1

Testing the universality of free fall with a two species atomic gravimeter — •Jonas Hartwig, Dennis Schlippert Schlippert, Ulrich Velte, Daniel Tiarks, Maic Zaiser, Vyacheslav Lebedev, Ernst Rasel, and Wolfgang Ertmer — Institut für Quantenoptik, Hannover

The universality of free fall (UFF) is one of the fundamental postulates of general relativity. It is well measured with macroscopic test masses in experiments like lunar laser ranging and torsion balance. An alternate approach employs atom interferometers which allow for a high precision measurement of forces utilising the quantum nature of matter. A comparison between two atomic isotopes was already demonstrated but only as a proof of principle experiment with limited accuracy.

In the CAPRICE Experiment we are comparing the free fall of potassium and rubidium atoms with a differential atomic gravimeter. This will lead to a precision test of the UFF with two quantum objects We use a 2D/3D MOT system together with an optical dipole trap for trapping and cooling the atomic ensembles. The light fields for the manipulation of both species use the same optical system, thus supressing most of the classical noise sources usually limiting measurement precision in a single species gravimeter.

We will present our first results with the single species rubidium gravimeter and show the progress of the system update to trap and manipulate potassium atoms. We also show our progress in working with an optical dipole trap of 1960 nm wavelength.