http://www.pnas.org/content/early/2018/05/30/1715105115.short (Publisher version)
1802.10288.pdf (Preprint), 2MB
Zou, Y.-Q., Wu, L.-N., Liu, Q., Luo, X.-Y., Guo, S.-F., Cao, J.-H., et al. (2018). Beating the classical precision limit with spin-1 Dicke states of more than 10,000 atoms. PNAS, 115(25), 6381-6385. doi:10.1073/pnas.1715105115.