Thermodynamic properties in triangular-lattice superconductors

The study of superconductivity arising from doping a Mott insulator has become a central issue in the area of superconductivity. Within the framework of the kinetic-energy-driven superconducting mechanism, we discuss the thermodynamic properties in triangular-lattice superconductors. It is shown that a sharp peak in the specific-heat appears at the superconducting transition temperature Tc, and then the specific-heat varies exponentially as a function of temperature for the temperatures T<Tc due to the absence of the d-wave gap nodes at the charge-carrier Fermi surface. In particular, the upper critical field follows qualitatively the charge-carrier pair gap type temperature dependence, and has the same dome-shaped doping dependence as Tc.