Spectral Collapse via Two-phonon Interactions in Trapped Ions

IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain(Dated: June 2, 2015)Two-photon processes have so far been considered only as resulting from frequency-matched second-orderexpansions of light-matter interaction, with consequently small coupling strengths. However, a variety of novelphysical phenomena arises when such coupling values become comparable with the system characteristic fre-quencies. Here, we propose a realistic implementation of two-photon quantum Rabi and Dicke models intrapped-ion technologies. In this case, effective two-phonon processes can be explored in all relevant parameterregimes. In particular, we show that an ion chain under bichromatic laser drivings exhibits a rich dynamics andhighly counterintuitive spectral features, such as interaction-induced spectral collapse.