Tailoring population transfer between two hyperfine ground states of Rb87

TL;DR

This paper explores the coherent control of population transfer in rubidium-87 atoms using STIRAP, demonstrating how additional excited states and atomic motion influence transfer efficiency and selectivity.

Contribution

It introduces a method to control population transfer by tuning light beams in multi-level rubidium-87 systems, accounting for effects of additional excited states and atomic motion.

Findings

Additional excited states impact transfer dynamics.

Proper tuning can block transfer channels for better control.

Atomic motion reduces transfer efficiency and selectivity.

Abstract

In this paper, we investigate the coherent control over a complex multi-level atomic system using the stimulated Raman adiabatic passage (STIRAP). Based on the example of rubidium-87 atoms, excited with circularly-polarized light at the D1 line, we demonstrate the ability to decompose the system into three- and four-level subsystems independently interacting with light beams. Focusing on the four-level system, we demonstrate that the presence of an additional excited state significantly affects the dynamics of the system evolution. Specifically, it is shown that, through the appropriate tuning of the light beams, some of the transfer channels can be blocked, which leads to better control over the system. We also demonstrate that this effect is most significant in media free from inhomogeneous broadening (e.g., Doppler effect) and deteriorates if such broadening is present. For instance, motion of atoms affects both the efficiency and selectivity of the transfer.