We study the complex nonlinear dynamics of the two-photon Dicke model in the
semiclassical limit by considering cavity and qubit dissipation. In addition to
the normal and super-radiant phases, another phase that contains abundant
chaos-related phenomena is found under balanced rotating and counter-rotating
couplings. In particular, chaos may manifest itself through period-doubling
bifurcation, intermittent chaos, or quasi-periodic oscillation, depending on
the value of qubit frequency. Transition mechanisms that exist in these three
distinct routes are investigated through the system's long-time evolution and
bifurcation diagram. Additionally, we provide a comprehensive phase diagram
detailing both the existence of stable fixed points and the aforementioned
chaos-related dynamics.Comment: 9 pages, 6 figure