An approach for studying the influence of uniaxial strain (pressure) on the temperature of the Bose-Einstein condensation of intersite bipolarons: possible implementation for RBa$_2$Cu$_3$O$_{7-\delta}$ cuprates

摘要

A universal approach is proposed to study the influence of strain (pressure)on the temperature of Bose-Einstein condensation of intersite bipolarons withinthe extended Holstein model. It is shown that uniaxial strain (pressure)derivatives of the temperature of such a Bose-Einstein condensation stronglydepend on the arrangement of ions in the lattice. In particular, they may bepositive or negative. A connection between the theoretically obtained results,along with the experimental data, on the influence of uniaxial pressure(strain) on $T_c$ of RBa$_2$Cu$_3$O$_{7-\delta}$ family cuprates is discussed.