Energy landscape and conical intersection points of the driven Rabi model

We examine the energy surfaces of the driven Rabi model, also known as the biased or generalized Rabi model, as a function of the coupling strength and the driving term. The energy surfaces are plotted numerically from the known analytic solution. The resulting energy landscape consists of an infinite stack of sheets connected by conical intersection points located at the degenerate Juddian points in the eigenspectrum. Trajectories encircling these points are expected to exhibit a nonzero geometric phase. (letter)