Positive and inverse isotope effect on superconductivity

TL;DR

This paper enhances BCS theory to explain both positive and inverse isotope effects in superconductors, clarifying the role of electron-phonon interactions and phonon-induced attraction.

Contribution

It introduces an improved model incorporating isotope effects into BCS theory, providing a clear explanation of the mechanisms behind positive and inverse isotope effects.

Findings

The model explains the occurrence of inverse isotope effects in superconductors.

It clarifies how electron-phonon interactions influence isotope effects.

The phonon-induced attraction is elucidated through electron Green functions.

Abstract

This article improves the BCS theory to include the inverse isotope effect on superconductivity. An affective model can be deduced from the model including electron-phonon interactions, and the phonon-induced attraction is simply and clearly explained on the electron Green function. The focus of this work is on how the positive or inverse isotope effect occurs in superconductors.