Quantum coherent effects in multi-Zeeman-sublevel atomic systems

This paper reports the experimental results on electromagneticallyinduced absorption (EIA) spectra observed in the system which doesnot satisfy completely the conditions given by Lezama {it et al}[1999 wx{Phys. Rev. {rm A}}{59} 4732]. EIA signals on thetransitions in the Cs $D_{2}$ line are able to be observed, where$F_{rm g} leftrightarrow F_{rm e}=F_{rm g}-1$ as open systems.Theoretical model of Lezama {it et al} is good for the case $F_{rmg} leftrightarrow F_{rm e}=F_{rm g}+1$, considering spontaneoustransfer of atomic coherences or populations this model is not ableto explain our experimental results obtained in the case $F_{rm g}leftrightarrow F_{rm e}=F_{rm g}-1$. This paper offers atheoretical model which is able to well explain the case $F_{rm g}leftrightarrow F_{rm e}=F_{rm g}-1$. It also uses thistheoretical model to explain the split and shift of EIA peaks, whichhave been obtained in experiments.