Dynamic cancellation of ac Stark shift for pulsed EIT/Raman optical   lattice clocks
  We propose a combination of Electromagnetically Induced Transparency (EIT)/Raman and pulsed spectroscopy techniques to accurately cancel frequency shifts arising from EIT fields in forbidden optical lattice clock transitions of alkaline earth atoms. Time-separated laser pulses are designed to trap atoms in coherent superpositions while eliminating off-resonance ac Stark contributions at particular laser detunings from the intermediate excited state. The scheme achieves efficient population transfer up to 60% with potential inaccuracy $<$ $10^{-17}$. Cancellation of external light shifts determined by a density matrix approach is confirmed by a complex wave-function formalism, sufficient at the mHz accuracy, under low field strengths or short interaction times. 
T. Zanon-Willette, A.D. Ludlow, S. Blatt, M.M. Boyd, E. Arimondo,* Jun   Ye