Optimal population transfer in driven-dissipative systems using adiabatic rapid passage

Adiabatic rapid passage (ARP) is extensively used to achieve efficient transfer of population between two levels of atomic systems. Landau and Zener accurately derived the transfer probability of ARP for closed systems following unitary dynamics and showed that this probability increases with higher drive amplitude. In this work, we adopt a quantum master equation approach to investigate the dissipative effects of the applied drive on the performance of ARP that is implemented using a linearly-chirped pulse on a two-level system interacting with its environment. From the Landau-Zener formula, the population transfer was known to be enhanced with increasing drive amplitude. However, we show that beyond a threshold value of the drive amplitude, the transfer probability is reduced because of the detrimental effect of the drive-induced dissipation. We report that the interplay between the two processes results in an optimal population transfer. Furthermore, we propose a phenomenological model that qualitatively explains the observed nonmonotonic behavior of the transfer. Using this model, we also estimate the optimum time at which the maximum population transfer occurs. We perform the analysis for rectangular as well as Gaussian pulse profiles and conclude that the use of a Gaussian pulse leads to more efficient transfer.