O-bridged electron pairing: the microscopic mechanism for high-temperature superconductivity in cuprates and nickelates

TL;DR

This paper proposes a novel electron pairing mechanism mediated by oxygen atoms in cuprates and nickelates, explaining key features of high-temperature superconductivity through an intuitive microscopic model.

Contribution

It introduces a new electron pairing scheme involving oxygen atoms as bridges, differing from previous theories, to explain high-temperature superconductivity in cuprates and nickelates.

Findings

Explains d-wave symmetry of Cooper pairs

Accounts for large superconducting gaps

Describes small electron-pair sizes

Abstract

Based on the energy level structure of neutral oxygen atom O and its anions, through in-depth analysis of the bonding process and formation mechanism of anion O$^{x-}$ ($1<x\leq{2}$) in oxide superconductors dominated by ionic bonds, we propose an emerging and important novel idea of electron pairing with oxygen atoms as a bridge, different from the previously proposed electronic pairing schemes. This microscopic electronic pairing image is very intuitive and vivid, which can naturally explain the d-wave symmetry of Cooper pairs, large superconducting energy gaps, and small electron-pair sizes in copper oxide high-temperature superconductors. It is the electron-electron pairing mechanism mediated by oxygen atoms that directly determines the unconventional high-temperature superconductivity of cuprates and nickelates.