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Applied Physics and Materials Science Seminar

Friday, September 29, 2023
2:00pm to 3:00pm
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Keck 142
Feedback control of ultracold atomic gases
Ryan Thomas, PhD, postdoctoral research fellow, Australian National University,


Cold atom interferometers currently provide some of the most precise and accurate measurements of acceleration and rotation in controlled laboratory settings. The challenge now is to move these interferometers from large, finely tuned apparatuses located in stable laboratories to compact devices suitable for field deployment on dynamic platforms. In this seminar, I will present preliminary results from an experiment aiming to use in situ feedback on a trapped atomic gas to reduce the effect of platform motion and improve atom flux. Using non-destructive measurement and control to remove energy from the lowest lying modes of a Bose-Einstein condensate, we show that we can reduce in-trap motion induced by a delta-kick to less than one phonon. When released from the trap, the condensate's run-to-run variation in mean velocity is reduced by a factor of three which will lead to reductions in errors due to wavefront aberrations and Coriolis effects. I discuss the prospects for extending this feedback scheme to more general cooling with the aim of providing an alternative method for producing degenerate Bose gases.

More about the Speaker:

Ryan Thomas completed his B.Sc. at Simon Fraser University before completing his M.Sc. in quantum optics at the University of Calgary. After working at the geophysics company CGG, he then moved to New Zealand in 2014 where he completed his Ph.D. at the University of Otago studying ultracold collisions using an optical atom collider. In 2020, Ryan moved to Canberra where he currently works as a postdoctoral research fellow at the Quantum Sensors Group studying atom interferometers and inertial sensors.


Prof. Keith Schwab. Please email [email protected] if you would like to meet with the speaker.

For more information, please contact Cecilia Gamboa by email at [email protected].