Thermodynamics and Phase Diagram of High Temperature SuperconductorsPhilippe Curty ; Hans Beck ; Date: Thu, 8 Jan 2004
16:59:16 GMT (412kb) Database: science-advisor/article/cond-mat/0401124 Journal: Phys. Rev. Lett. 91, 257002 (2003)Subject:Superconductivity; Statistical Mechanics; Strongly CorrelatedElectrons; Data Analysis, Statistics and Probability |cond-mat.supr-con cond-mat.stat-mech cond-mat.str-el physics.data-anAbstract:Thermodynamicquantities are derived for superconducting and
pseudogap regimes bytaking into account both
amplitude and phase fluctuations of thepairing field. In the normal (pseudogap) state of the underdopedcuprates, two domains have to be distinguished: near thesuperconducting region, phase correlations are important up to thetemperature $T_phi$. Above $T_phi$, the pseudogap region is onlydetermined by amplitudes, and phases are uncorrelated. Our calculationsshow excellent quantitative agreement with specific heat and magneticsusceptibility experiments on cuprates. We find that the mean fieldtemperature $T_0$ has a similar doping dependence as the pseudogaptemperature $T^*$, whereas the pseudogap energy scale is given by theaverage amplitude above $T_c$.