text: FIG. 4: Top - a conductivity plot for the BCSI case in the 
  presence of a lattice. The parameters are ∆ = 30 meV , Γ = 
  3.5 meV . Bottom – the behavior of Kubo sums. Note that (a) 
  the spectral weight in the NS is always greater in the SCS, (b) 
  the spectral weight decreases with Γ, and (c) the diﬀerence 
  between NS and SCS decreases as Γ increases. 
  
  FIG. 5: The evolution of optical integral in NS(top) and 
  SCS(bottom) for BCSI case. Plots are made for clean limit 
  (solid lines, Γ = 3.5 meV ) and dirty limit (dashed lines, 
  Γ = 150 meV ) for ∆ = 30 meV . Observe that (a) W (0) = 0 
  in the NS, but has a non-zero value in the SCS because of the 
  δ-function (this value decreases in the dirty limit), and (b) 
  the ﬂat region in the SCS is due to the fact that σ 
  (ω) = 0 for 
  Ω < 2∆. Also note that 
  95% of the spectral weight is 
  recovered up to 1eV 
  
  ′ 