Chirped-pulse adiabatic population transfer in a dissipative three-level ladder: Bath-dependent transfer via the multiple Davydov ansatz
Phys. Rev. A 114, 043721 – Published 15 October, 2026
DOI: https://doi.org/10.1103/7kc4-gxhr
Abstract
Rapid adiabatic passage, which enables complete population transfer via a frequency-chirped laser pulse, is valued for its robustness to pulse-area fluctuations in quantum-dot control. Previous work by Werther and Grossmann [M. Werther and F. Grossmann, Phys. Rev. A 102, 063710 (2020)] showed that strong coupling to a super-Ohmic phonon bath can further stabilize this robustness in a two-level system, an effect invisible to Markovian treatments. We extend this framework to a three-level quantum-dot-like ladder (ground state, single exciton, biexciton) coupled to a super-Ohmic phonon bath, using the multiple Davydov ansatz with the Dirac-Frenkel variational principle. Systematic multidimensional sweeps over pulse area, temporal chirp, and bath coupling strength reveal a qualitative bifurcation governed by the ladder's resonance structure. For a detuned ladder, the bath stabilizes and smooths population transfer into the single-exciton state, sustaining near-unity fidelity across all coupling strengths studied and preferring positive chirp. This extends the two-level bath-stabilization picture to three-level systems. In contrast, for a double-resonant ladder, the same bath coupling disrupts coherent transfer: population is distributed across all three levels, the maximum single-exciton fidelity becomes nonmonotonic in coupling strength, and the preferred chirp direction reverses relative to the detuned case. We trace the nonmonotonic dependence to bath-induced dephasing that distributes population incoherently across all three levels, a redistribution mechanism with no two-level analog. The observed chirp-sign reversal constitutes a falsifiable experimental prediction for distinguishing the two regimes without requiring independent spectroscopic knowledge of the biexciton binding energy.
