Experimental Investigation of the Dark Pseudoresonance on the D1 Line of   the 87Rb Atom Excited by a Linearly Polarized Field
  The measurements of the metrological characteristics (amplitude, width, and shift in the magnetic field) of the dark pseudoresonance, which was proposed by Kazakov et al. [quant-ph/0506167] as the reference resonance for an atomic frequency standard, are reported. It has been shown that the characteristics of the pseudoresonance are worse than those of the unsplit electromagnetically induced transparency resonance for the excitation scheme with the lin||lin polarization on the D1 line of the 87Rb atom. 
Sergei Zibrov, V. L. Velichansky, A. S. Zibrov, A. V. Taichenachev,   and V. I. Yudin