The relationship between the pseudo-gap and the spin pairing dipolar superconducting gap in the Sn-doped Hg-1223 high temperature superconductors

The Sn-doped mercury-based high temperature superconductors, (Hg_1-xSn_x)Ba₂Ca₂Cu₃O _8+δ, were used to study the pseudo-gap phenomenon. By means of In[1/ρ(T) - 1/ρ_N(T)] vs. 1/T plots we found three characteristic temperatures T*, T_S and T_F, which describe the role of pseudo-gap phenomenon. From the stated plots, we are able to estimate the magnitude of the pseudogap, Δ_PG, for our samples. During lowering temperature from T_F to T_C, the pseudo-gap Δ_PG changes smoothly into the spin pairing dipolar superconducting gap Δ_SPDS, when the Fermi kinetic energy shrinks to zero at the critical temperature T_C. The spin pairing dipolar superconducting gap can be related to the total superconducting gap Δ_T i.e. Δ_SFDS = √2/3δ_T Hence the cuprate's superconducting gap is given by 2Δ_T = 3.52√3k_BT_c. The spin pairing dipolar superconducting gap is experimentally shown to be smaller than the dipolar pseudo-gap, Δ_PG.