Observations of Autler-Townes Splitting of Zeeman-resolved Electromagnetically Induced Transparency Signal in Cs Rydberg Atoms

To isolate the Autler-Townes splitting induced by a single selected THz transition in a Cs Rydberg atom, a Zeeman-resolved EIT (electromagnetically induced transparency) signal was obtained in a high magnetic field. The electronic state was controlled by the polarizations of two lasers exciting the Cs atoms and the chosen magnetic quantization axis. Applying a THz wave with controlled polarization then enabled an observation of the Autler-Townes splitting induced by its coupling to a single dipole transition.