Theme 1 colloquium: 'Collisional loss of ultracold molecules' (Lecture)
- Tuesday 1 October 2019Add to my calendar
- from 16:00
dr. Tijs Karman (Harvard University, USA)
Ultracold polar molecules are a promising platform for upcoming quantum technologies such as quantum computing and quantum simulation. Currently, applications are limited by loss due to molecule-molecule collisions. Surprisingly, effective two-body loss is observed even for chemically stable molecules. For some time, the only explanation o_ered was that of \sticky collisions"; the formation of long-lived collision complexes that mediate the loss.
We show that the sticking times were previously overestimated by orders of magnitude, and sticking alone cannot explain the experimental observations. Instead, we show that excitation of collision complexes by the laser used to trap the molecules leads to the e_ective two-body loss observed experimentally. Possible solutions include the use of longer laser wavelengths, repulsive box potentials, or shielding from molecular collisions . Shielding may be achieved using microwaves that induce repulsive long-range interactions between ultracold polar molecules .
 Christianen, Zwierlein, Groenenboom, and Karman, Phys. Rev. Lett., 123, 123402 (2019)
 Karman and Hutson, Phys. Rev. Lett., 121, 163401 (2018)
dr. Joost Bakker & dr. Gilles de Wijs