Enhancement of superconducting transition temperature by the additional second neighbor hopping t' in the t-J model

TL;DR

This paper investigates how adding a second neighbor hopping term t' in the t-J model enhances the superconducting transition temperature, supporting a kinetic energy-driven pairing mechanism consistent with BCS theory.

Contribution

It demonstrates that the second neighbor hopping t' significantly increases the superconducting transition temperature within the t-J model, aligning with BCS formalism despite a kinetic energy-driven pairing mechanism.

Findings

t' enhances the superconducting transition temperature

BCS formalism remains valid for cuprates

Kinetic energy-driven pairing explains superconductivity

Abstract

Within the kinetic energy driven superconducting mechanism, the effect of the additional second neighbor hopping t' on the superconducting state of the t-J model is discussed. It is shown that t' plays an important role in enhancing the superconducting transition temperature of the t-J model. It is also shown that the superconducting-state of cuprate superconductors is the conventional Bardeen-Cooper-Schrieffer like, so that the basic Bardeen-Cooper-Schrieffer formalism is still valid in quantitatively reproducing the doping dependence of the superconducting gap parameter and superconducting transition temperature, and electron spectral function at $(\pi,0)$ point, although the pairing mechanism is driven by the kinetic energy by exchanging dressed spin excitations.