Supercell band calculations and correlation for high-$T_C$ copper oxide superconductors

TL;DR

This paper reviews first-principles band calculations and models for high-temperature copper oxide superconductors, emphasizing the role of modest DFT corrections and spin fluctuations in their superconducting mechanism.

Contribution

It demonstrates that modest corrections to approximate DFT can induce AFM order and highlights the importance of spin fluctuations interacting with phonons for superconductivity.

Findings

Modest DFT corrections can induce AFM order.

Spin fluctuations interacting with phonons are crucial for superconductivity.

First-principles calculations describe properties of high-$T_C$ copper oxides.

Abstract

First principle band calculations based on local versions of density functional theory (DFT), together with results from nearly free-electron models, can describe many typical but unusual properties of the high-$T_C$ copper oxides. The methods and a few of the most important results are reviewed. Some additional calculations are presented and the problems with the commonly used approximate versions of DFT for oxides are discussed with a few ideas for corrections. It is concluded that rather modest corrections to the approximate DFT, without particular assumptions about strong correlation, can push the ground state towards anti-ferro magnetic (AFM) order. Spin fluctuations interacting with phonons are crucial for the mechanism of superconductivity in this scenario.