Figure 5
From: Finite-temperature scaling of trace distance discord near criticality in spin diamond structure
Several typical quantum correlations, (a) concurrence 
, (b) Hellinger distance 
, (c) quantum discord 
, and (d) trance distance discord 
as a function of parameter Δ around the points(Δ,h) = (1,0) at various temperatures T, respectively. Obviously, they are all smooth functions of Δ. However, the first-derivatives for 
, 
and 
would exhibit an unexpected discontinuity point Δf, which is unfortunately not a real critical point except normal discontinuity point Δc for the QPT.
