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

TL;DR

This paper investigates how uniaxial strain affects the Bose-Einstein condensation temperature of intersite bipolarons, providing theoretical insights that align with experimental observations in high-$T_c$ superconducting films.

Contribution

It introduces a generalized model accounting for uniaxial strain effects on bipolaron condensation temperature within the Extended Holstein-Hubbard framework.

Findings

Calculated strain derivatives of $T_{BEC}$ match experimental data.

Uniaxial strain significantly influences the bipolaron condensation temperature.

The model explains variations in $T_c$ in La-based high-$T_c$ films.

Abstract

We 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.