Florian Schreck - Continuous Bose-Einstein condensation and superradiant clocks

Ultracold quantum gases are excellent platforms for quantum simulation and sensing. So far these gases have been produced using time-sequential cooling stages and after creation they unfortunately decay through unavoidable loss processes. This limits what can be done with them. For example it becomes impossible to extract a continuous-wave atom laser, which has promising applications for precision measurement through atom interferometry [1]. I will present how we achieve continuous Bose-Einstein condensation and create condensates (BECs) that persist in a steady-state for as long as we desire. Atom loss is compensated by feeding fresh atoms from a continuously replenished thermal source into the BEC by Bose-stimulated gain [2]. We are now using our new techniques also to tackle another challenge: the creation of continuously operating optical atomic clocks, which promise higher measurement bandwidth and better short term stability than traditional optical clocks that operate in a pulsed manner [3,4,5,6]. I will present our progress in building superradiant and zero-deadtime clocks.

References

1. N. P. Robins, P. A. Altin, J. E. Debs, and J. D. Close, Atom lasers: Production, properties and prospects for precision inertial measurement, Physics Reports 529, 265 (2013).
2. C.-C. Chen, R. González Escudero, J. Minář, B. Pasquiou, S. Bennetts, and F. Schreck, Continuous Bose-Einstein condensation, Nature 606, 683 (2022).
3. M. A. Norcia, M. N. Winchester, J. R. K. Cline, and J. K. Thompson, Superradiance on the millihertz linewidth strontium clock transition, Sci. Adv. 2, e1601231 (2016).
4. J. Chen, Active Optical Clock, Chinese Science Bulletin 54, 348 (2009).
5. D. Meiser, J. Ye, D. R. Carlson, M. J. Holland, Prospects for a Millihertz-Linewidth Laser, PRL 102, 163601 (2009).
6. M. Schioppo et al., Ultrastable optical clock with two cold-atom ensembles, Nature Photonics 11, 48 (2017).