Buzzi, M., Jotzu, G., Cavalleri, A., Cirac, J.I., Demler, E.A., Halperin, B.I., Lukin, M.D., Shi, T., Wang, Y., Podolsky, D., 2021. Higgs-Mediated Optical Amplification in a Nonequilibrium Superconductor 11.. https://doi.org/10.1103/physrevx.11.011055