Possibility for high-temperature superconductivity

A new mechanism of superconductivity in semiconductors and semimetals based on the metallic phase of the exciton was proposed by Abrikosov. He estimated the critical temperature for CuCl to be of order 100°K by employing the weak coupling BCS formula. It is shown here that the strong-coupling limit is more appropriate and that Tc is then estimated to be of the order 1°K. © 1979 The American Physical Society.