Zero-quantum dual-comb spectroscopy of collective resonances in rubidium vapor
Bachana Lomsadze, Johnason Yao, Hankang Gao +1 more
We report dual-comb spectroscopy of the collective zero-quantum response of rubidium atoms. The observed signals include two-atom collective resonances at 2( ω D 2 − ω D 1 ), ω 5 P 3/2 →5 D − ω D 2 , ω 5 P 3/2 →5 D − ω D 1 , and ( ω D 2 − ω D 1 )+( ω 5 P 3/2 →5 D − ω D 1 ), as well as higher-order three-atom resonances. Unlike double-quantum spectroscopy, which probes sum-frequency resonances of multiple atoms, the zero-quantum pathway probes difference-frequency correlations between optical transitions. In a dual-comb implementation, these signals are independent of the carrier-envelope offset frequencies of both combs, enabling rapid measurements without active carrier-envelope offset stabilization. These results show that zero-quantum dual-comb spectroscopy is a powerful approach for probing collective coherences and many-body correlations in atomic systems.
Optics Letters•Oct 9, 2026•0 citations