The dark resonances in the case of the absorption of optical radiation   in double tunneling-coupled quantum wells
  This work is devoted to the research of conditions of the dark resonance (coherent population trapping) of the interaction of the laser radiation with tunneling-coupled quantum wells. The phase sensitive dependence of dark resonances has been investigated. We obtained that destruction as well as restoration of the dark resonances of the coherent population trapping is possible in dependence on algebraic sum of the phases of exciting fields. It is shown that the phase variation of exciting fields influences on the absorption and dispersion of the probe field in a medium with quantum wells. 
A. N. Litvinov, K. A. Barantsev, B. G. Matisov, G. A. Kazakov, Yu. V.   Rozhdestvensky
quant-ph