The two-photon ladder climbing (successive two-photon Landau-Zener-type transitions) in a chirped quantum nonlinear oscillator and its classical limit (subharmonic autoresonance) are discussed. An isomorphism between the chirped one- and two-photon resonances in the system is used in calculating the threshold for the phase-locking transition in both the classical and quantum limits. The theory is tested by solving the Schrödinger equation in the energy basis and illustrated via the Wigner function in phase space.
|Physical Review A - Atomic, Molecular, and Optical Physics
|Published - 31 May 2013