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Q: Fachverband Quantenoptik und Photonik
Q 37: Precision Measurements and Metrology II
Q 37.2: Talk
Wednesday, March 13, 2019, 14:15–14:30, S SR 111 Maschb.
Time averaged optical potentials for fast BEC creation — •H. Albers1, A. Rajagopalan1, W. Ertmer1, D. Schlippert1, E.M. Rasel1, and The PRIMUS-Team2 — 1Institut für Quantenoptik, Leibniz Universität Hannover — 2ZARM, Universität Bremen
Quantum sensors employing cold atoms are sampling devices.
Ultra cold atoms are crucial for improving the accuracy of inertial sensors.
Achieving high repetition rates with ultra cold atoms, such as Bose-Einstein condensates, is challenging as evaporative cooling is time consuming.
In optical dipole traps forced evaporative cooling is achieved by lowering the optical power in order to reduce the trap depth.
This results in a reduction of the trap frequencies and extended the rethermalisation time.
To disentangle trap depth and frequency we use a time averaged optical potential.
The potential is realized by modulating the horizontal positions of the crossed dipole trap beams to create a effective harmonic potential.
After trapping the reduction of both the optical power and the modulation amplitude leads to a quasi pure BEC of a few 105 87Rb atoms within 3 seconds of forced evaporative cooling.
In comparison to evaporation without modulation amplitude reduction this is an increase in speed by a factor of 3.
This talk will focus on the implementation of time averaged optical potential in our existing setup and shows the path towards atomic ensembles with ultra cold effective temperatures at a high repetition rate.
The PRIMUS-project is supported by the German Space Agency DLR with funds provided by the Federal Ministry for Economic Affairs and Energy (BMWi) under grant number DLR 50 WM 1641.