An effect of the uniaxial strain on the temperature of Bose–Einstein condensation of the intersite bipolarons

Abstract

a b s t r a c tWe have studied an effect of uniaxial strain to the temperature of Bose-Einstein condensation of intersite bipolarons within the framework of extended Holstein-Hubbard model. Uniaxial lattice strains are taken into an account by introducing a generalized density-displacement type force for electron-lattice interaction. Associating the superconducting critical temperature T c with the temperature of Bose-Einstein condensation T BEC of intersite bipolarons we have calculated strain derivatives of T BEC and satisfactorily explained the results of the experiments on La-based high-T c films.