Analysis of Electronic Heat Capacity of YBa2Cu3O7-δ Superconductor

Expressions are obtained for the electronic heat capacity (EHC) of high-T-c superconductors (HTS) using the many body quantum dynamical theory of electron Green's functions via a generalized Hamiltonian that incorporates the effects of electron-phonon interactions, anharmonicities and defects. It is remarkable to note that the electron-phonon coupling constant (g(k)) is present in all the contributions of EHC and support to phonon mediated paring mechanism to high-T-c superconductivity (HTSC). The automatic emergence of pairons during the calculation is the special feature of theory. The present theory reveals that density of states reside in the center of finding of EHC expressions through Green's function. The obtained expressions of EHC are further analyzed for YBa2Cu3O7-delta (YBCO) superconductor and specify that electron-phonon interactions, impurities and anharmonicities play important role in EHC behavior.