Competing stripe and magnetic phases in the cuprates from first principles

Abstract

Significance High-temperature superconductivity, first discovered in materials with copper-oxide planes, is still not well understood. Cuprates exhibit complex phase diagrams under temperature and doping and have not been amenable to first-principles description using previous density functionals, but the recent SCAN functional correctly predicts many properties of the undoped and doped YBCO compounds. In the oxygen-doped YBa 2 Cu 3 O 7 , SCAN finds many competing states with charge and spin stripes. Thermal energies will mix these states, creating fluctuations of the spin moments on the copper atoms in the pseudogap phase from which superconductivity emerges. Our study suggests a paradigm in which the physics of the mysterious pseudogap phase in the cuprates is encoded through a landscape of underlying competing phases in the material.