Creation of particle-hole superposition states in graphene at   multiphoton resonant excitation by laser radiation
  Nonlinear dynamics of establishment of electron-hole coherent superpositions states in graphene by multiphoton resonant excitation of interband transitions in laser fields is considered. The single-particle time dependent density matrix for such a quantized system is calculated in the multiphoton resonant approximation. The dependence of Rabi oscillations of Fermi-Dirac sea in graphene on the time, momentum, and photon number at multiphoton laser-excitation is analyzed. 
H. K. Avetissian, A. K. Avetissian, G. F. Mkrtchian, Kh. V. Sedrakian
cond-mat.mes-hall physics.optics quant-ph