Critical temperature

摘要

Critical temperature, T_c, is the major parameter of physics of superconductivity. Its value depends on the strength of the attractive interaction lambda , the energy scale DELTA E ( DELTA E= OMEGA = OMEGA _D for the conventional phonon mechanism, OMEGA _D is the Debay temperature), and the Coulomb repulsion mu ~*. Assume, first, that mu ~*=0. According to the BCS theory, the value of T_c is determined by the famous expression [1] T_c=1.14h OMEGA -tildee~(1/ lambda ) (1)