Opening of pseudogaps due to superconducting critical fluctuations in   quasi-two dimensions
  We examine the role of the anisotropy of superconducting thermal critical fluctuations in the opening of pseudogaps in quasi-two dimensions. When the anisotropy of coherence or correlation lengths of the fluctuations is large enough and critical temperatures T_c are high enough, the energy dependence of the selfenergy deviates from that of Landau's normal Fermi liquid in critical regions; its imaginary part has no minimum at the chemical potential. Prominent pseudogaps open in such a non-Fermi liquid phase. Pseudogaps must be absent or subtle in quasi-two dimensional superconductors with low T_c and almost isotropic three dimensional superconductors. 
Fusayoshi J. Ohkawa