Robust population transfer in atomic beams induced by Doppler shifts

TL;DR

This paper investigates how Doppler shifts influence adiabatic population transfer in atomic beams, revealing conditions for robust control of atomic states despite atomic motion and parameter fluctuations.

Contribution

It demonstrates the role of Doppler shifts in population transfer and shows how to achieve robust atomic state control in moving atomic beams.

Findings

Doppler shifts significantly affect population transfer outcomes.

Slow atoms reliably reach the target state regardless of pulse sequence.

Fast atoms' target state depends on pulse order and Doppler effects.

Abstract

The influence of photon-momentum recoil on adiabatic population transfer in an atomic three-level lambda system is studied. It is shown that the Doppler frequency shifts, due to atomic motion can play an important role in adiabatic population transfer processes of atomic internal states by a pair of laser fields. For the limiting case of slow atoms ( Doppler shift much smaller than the photon recoil energy) the atoms occupy the same target state regardless of the order of switching of laser fields, while for the case of fast atoms interacting with the intuitive sequence of pulses, the target state is the intermediate atomic state. It is shown that these processes are robust with respect to parameter fluctuations, such as the laser pulse area and the relative spatial offset (delay) of the laser beams. The obtained results can be used for the control of temporal evolution of atomic populations in atomic beams by externally adjustable Doppler shifts.