Four-state N-atom as a simple theoretical model for electromagnetically induced absorption

Taichenachev, A. V.; Tumaikin, A. M.; Yudin, V. I.

Four-state N-atom as a simple theoretical model for electromagnetically induced absorption

Authors

Taichenachev, A. V.

Tumaikin, A. M.

Yudin, V. I.

Description

A simple theoretical model describing the positive sign of subnatural-width absorption resonances in the recent experiment of Akulshin and co-workers (Phys. Rev. A, {\bf 57}, 2996 (1998)) is proposed. An analytical expression for the linear response to the weak probe field is found in the low-saturation limit with respect to the control field. It is shown that the positive sign of subnatural resonance is caused by the spontaneous transfer of the light-induced coherence from the excited level to the ground one.
RevTeX 4 pages, 3 ps figures