Jul 17 – 22, 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

Evaporation and Large Arrays of Laser Cooled CaF Molecules

Jul 20, 2022, 5:00 PM
1h 30m
Hart House (Hart House)

Hart House

Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Degenerate gases, many-body physics, and quantum simulation Poster session


The wide-ranging scientific applications of ultracold molecules have inspired significant efforts in cooling and controlling molecules in the single quantum state level. Many potential applications are still hampered by the finite temperatures experimentally achieved. As temperatures are reduced further, motional decoherence rates are suppressed and fidelities increase, opening new opportunities for quantum simulations and computation. One of the most successful cooling methods for atomic species, evaporative cooling, requires a high elastic rate and large ratio of elastic to inelastic collisions. While this ratio is typically low for most molecules, using microwaves we engineer a repulsive barrier between molecules, shielding inelastic losses while increasing the rate of elastic collisions. Using optically trapped CaF molecules, we demonstrate that the elastic rate can be increased while the inelastic loss is suppressed to reach a ratio of 50. By adiabatically lowering the trap depth to force evaporate of the hottest molecules, we observed a drop in temperature of the sample when shielding was enabled compared to a control sample without shielding. Future improvements in initial density and number would allow for more effective evaporation. Evaporative cooling is useful for bulk samples, but to use molecules in single optical tweezer arrays requires single particle cooling. To this end we report progress towards sideband cooling of CaF molecules to the ground motional state of an optical tweezer.

Presenter name Scarlett S. Yu
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Primary authors

Ms Scarlett S. Yu (Harvard University) Dr Loic Anderegg (Harvard University) Mr Yicheng Bao (Harvard University) Mr Sean Burchesky (Harvard University) Mr Derick Gonzalez-Acevedo (Harvard University) Prof. Eunmi Chae (Korea University) Prof. Kang-Kuen Ni (Harvard University) Prof. Wolfgang Ketterle (MIT) Prof. John Doyle (Harvard University)

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