The effective conjugation symmetry that arises in the rotating wave frame is the analogue of the discrete symmetry in field theory. Breaking this effective conjugation symmetry leads to asymmetries between up- and down- chirped excitation in quantum optical systems. We use semiclassical quantum optics theory to describe these processes and experimentally characterize the asymmetry in the optical response in chirped, two-color saturated absorption spectroscopy (SAS) in an atomic vapor cell. Doing so demonstrates a theoretical and phenomenological correspondence to the simplest model of leptogenesis, the process by which our universe purportedly went from equal amounts of matter and antimater to its present matter excess. The understanding of the asymmetry as due to a broken discrete symmetry under chirp appears to illuminate the underlying processes responsible for other chirp asymmetries previously noted in the literature.
