%0 Journal Article %J arXiv:1611.00797 %D 2016 %T Steady-state superradiance with Rydberg polaritons %A Zhe-Xuan Gong %A Minghui Xu %A Michael Foss-Feig %A James K. Thompson %A Ana Maria Rey %A Murray Holland %A Alexey V. Gorshkov %X

A steady-state superradiant laser can be used to generate ultranarrow-linewidth light, and thus has important applications in the fields of quantum information and precision metrology. However, the light produced by such a laser is still essentially classical. Here, we show that the introduction of a Rydberg medium into a cavity containing atoms with a narrow optical transition can lead to the steady-state superradiant emission of ultranarrow-linewidth nonclassical light. The cavity nonlinearity induced by the Rydberg medium strongly modifies the superradiance threshold, and leads to a Mollow triplet in the cavity output spectrumthis behavior can be understood as an unusual analogue of resonance fluorescence. The cavity output spectrum has an extremely sharp central peak, with a linewidth that can be far narrower than that of a classical superradiant laser. This unprecedented spectral sharpness, together with the nonclassical nature of the light, could lead to new applications in which spectrally pure quantum light is desired.

%B arXiv:1611.00797 %8 2016/11/02 %G eng %U https://arxiv.org/abs/1611.00797 %0 Journal Article %J Physical Review Letters %D 2012 %T Steady-state many-body entanglement of hot reactive fermions %A Michael Foss-Feig %A Andrew J. Daley %A James K. Thompson %A Ana Maria Rey %X Entanglement is typically created via systematic intervention in the time evolution of an initially unentangled state, which can be achieved by coherent control, carefully tailored non-demolition measurements, or dissipation in the presence of properly engineered reservoirs. In this paper we show that two-component Fermi gases at ~\mu K temperatures naturally evolve, in the presence of reactive two-body collisions, into states with highly entangled (Dicke-type) spin wavefunctions. The entanglement is a steady-state property that emerges---without any intervention---from uncorrelated initial states, and could be used to improve the accuracy of spectroscopy in experiments with fermionic alkaline earth atoms or fermionic groundstate molecules. %B Physical Review Letters %V 109 %8 2012/12/4 %G eng %U http://arxiv.org/abs/1207.4741v1 %N 23 %! Phys. Rev. Lett. %R 10.1103/PhysRevLett.109.230501