Spin density wave in oxypnictide superconductors in a three-band model

TL;DR

This paper investigates the spin density wave phenomena in oxypnictide superconductors using a three-band model, revealing how various interactions influence SDW formation and phase transitions.

Contribution

It introduces a three-band model analysis of SDW in oxypnictides, highlighting the effects of Coulomb repulsion and Hund's coupling on magnetic ordering.

Findings

SDW peaks around the M point indicate stripe-like spin order

Intra-band Coulomb enhances SDW, Hund's coupling weakens it

A resonance at the Γ point signals transition to paramagnetic phase

Abstract

The spin density wave and its temperature dependence in oxypnictide are studied in a three-band model. The spin susceptibilities with various interactions are calculated in the random phase approximation(PPA). It is found that the spin susceptibility peaks around the M point show a spin density wave(SDW) with momentum (0, $\pi$) and a clear stripe-like spin configuration. The intra-band Coulomb repulsion enhances remarkably the SDW but the Hund's coupling weakens it. It is shown that a new resonance appears at higher temperatures at the $\Gamma$ point indicating the formation of a paramagnetic phase. There is a clear transition from the SDW phase to the paramagnetic phase.