



01196nas a2200133   4500008004100000245005300041210005100094260001500145490000800160520081600168100001800984700002301002856003701025       2022                        eng d00aApproximating the two-mode two-photon Rabi model0 aApproximating the twomode twophoton Rabi model  c01/17/20220 v4223 a<p>The Rabi model describes the simplest nontrivial interaction between a few-level system and a bosonic mode, featuring in multiple seemingly unrelated systems of importance to quantum science and technology. While exact expressions for the energies of this model and its few-mode extensions have been obtained, they involve roots of transcendental functions and are thus cumbersome and unintuitive. Utilizing the symmetric generalized rotating wave approximation (S-GRWA), we develop a family of approximations to the energies of the two-mode two-photon Rabi model. The simplest elements of the family are analytically tractable, providing good approximations in regimes of interest such as ultra- and deep-strong coupling. Higher-order approximate energies can be used if more accuracy is required.&nbsp;</p>1 aWu, David, H.1 aAlbert, Victor, V.  uhttps://arxiv.org/abs/2012.06994