An extended pair tunneling model: studies on bilayer splitting and some superconducting state properties

TL;DR

This paper extends the pair tunneling model for cuprates by including interlayer single particle hopping, explaining bilayer splitting absence and matching experimental superconducting gap temperature dependence.

Contribution

It introduces an extended pair tunneling model with interlayer hopping, aligning theoretical predictions with experimental observations in cuprates.

Findings

Bilayer splitting is absent in ARPES data, consistent with the model.

Superconducting gap temperature dependence matches experimental data.

A linear probability factor P yields the best fit to experiments.

Abstract

We consider an extended version of the pair tunneling model including interlayer single particle hopping (ISPH) as a complementary process to pair tunneling. The normal state gap, as found in cuprates, is taken to suppress the effective ISPH in conformity with the experimental observations, and this in turn enhances the pair tunneling process. The effective ISPH involves a probability factor P for which we consider two choices and provide phenomenological arguments in favour of them. We address the issue of bilayer splitting by calculating the spectral density function and corresponding photoemission intensity curves and show that our calculations conform with the absence of bilayer splitting observed in ARPES experiments on Bi2212. We have also studied the temperature variation of the superconducting gap and ratio of the superconducting gap to T_c. Our results, obtained for both the choices of P, are reasonably in good agreement with those from experiments on cuprate superconductors. A linear T-dependent choice of P, however, yields a precise match to the experimantal data of the temperature varying superconducting gap.