Continuous Collective Strong Coupling of Strontium Atoms to a High Finesse Ring Cavity
Julia Cline, Vera M. Schäfer, Zhijing Niu, Dylan J. Young, Tai Hyun Yoon, James K. Thompson
Abstract
We demonstrate continuous loading and strong collective coupling of atoms to a high finesse ring cavity. A series of spatially separated laser cooling stages delivers a continuous flux of 2.1(3)×10^{7} ^{88}Sr atoms/s into an intracavity magic wavelength lattice where the atoms are deterministically transported inside the ring cavity. We observe a continuous atom-cavity vacuum Rabi splitting, demonstrating the first steady-state strong collective coupling on a narrow linewidth atomic transition. This Letter opens the path to future continuous cold atom devices, such as a continuous wave superradiant laser with millihertz linewidth and low vibration sensitivity, enabling searches for new physics and technologies.