Dynamics of Fock states in traveling pulses

Abstract

The quantum state of a traveling light pulse can qualitatively change the excitation dynamics of a two-level atom. We investigate this dependence for coherent and Fock input states using a virtual-cavity formulation with matched input and output temporal profiles. Analytical treatment of the master equation and numerical simulations show that coherent pulses produce damped Rabi oscillations, whereas Fock pulses can exhibit a partial recovery of the oscillation amplitude in the trailing part of the pulse. We examine how coupling to an auxiliary temporal mode and radiative loss shape this recovery. We also establish a connection with stimulated Raman adiabatic passage through an exact many-photon dark state and derive the associated adiabaticity condition. The observed recovery occurs away from ideal dark-state following. These results distinguish transient recovery in traveling-pulse scattering from conventional cavity collapse and revival, and clarify the scope of an adiabatic-transfer interpretation.