Floquet-Landau-Zener interferometry: Usefulness of the Floquet theory in pulse-laser-driven systems

We develop the Landau-Zener transfer matrix theory for instantaneous Floquet states (IFSs) quantum systems driven by strong pulse lasers. Applying this to excitation probability in two-level systems, we show unexpectedly good quantitative agreements few-cycle pulses. This approach enables us qualitatively understand probability's peculiar behaviors as path interference between IFSs. also study pulse-width dependence, finding that Floquet-state interpretation remains useful shorter pulses down 2-cycle ones present model. These results imply is meaningful experimental lasers if applied appropriately sense of