High-quality level-crossing resonances under counterpropagating circularly polarized light waves for applications in atomic magnetometry

Level-crossing (LC) resonances in a buffer-gas-filled cesium vapor cell are studied under counterpropagating pump and probe light waves with opposite circular polarizations. The waves excite the D$_1$-line ground-state level $F_g$$=\,$$4$, while a transverse magnetic field (${\rm B}_x$$\perp$${\rm k}$) is scanned around zero to observe the resonance of electromagnetically induced absorption (EIA). It is shown that adding the pump light wave significantly improves the properties of the resonances in comparison with the commonly used scheme with a single light wave. As far as a small vapor cell ($\approx\,$0.1 cm$^3$) at relatively low temperature ($\approx\,$45-60$\,^\circ$C) is utilized, the results have good prospects for developing a low-power miniaturized atomic magnetometer.