Temperature dependence of the electron chemical potential in YBa2Cu3O

TL;DR

This paper investigates how the electron chemical potential in YBa2Cu3O varies with temperature near the superconducting transition, highlighting discrepancies between theory and experiment and proposing charge transfer as an explanation.

Contribution

It introduces a model considering charge transfer between chains and planes to explain the temperature dependence of the chemical potential in YBa2Cu3O.

Findings

Experimental and theoretical values of the chemical potential derivative jump are inconsistent.

Charge transfer between chains and planes affects the chemical potential behavior.

Theoretical calculations incorporating charge transfer better match experimental data.

Abstract

We study the behaviour of the electronic chemical potential in YBa2Cu3O near the superconducting transition using the spin-wave exchange theory of pairing. We find that the experimental value of the jump in the temperature derivative of the chemical potential is inconsistent with the theoretical value calculated under the assumption of constant hole concentration. It is suggested that charge transfer between chains and planes takes place and corresponding calculations are done.