Distorted magnetic orders and electronic structures of tetragonal FeSe from first-principles

TL;DR

This study employs advanced density-functional theory to analyze magnetic orders and electronic structures in tetragonal FeSe, revealing the stability of striped antiferromagnetic phases and their implications for understanding FeSe and related materials.

Contribution

The paper provides first-principles calculations showing striped antiferromagnetic order as energetically favorable in FeSe, with insights into magnetic interactions and electronic structures.

Findings

Striped antiferromagnetic order is more stable than checkerboard order.

Inter-layer magnetic interaction is very weak.

Calculated spin coupling constants and magnetic moments.

Abstract

We use the state-of-the-arts density-functional-theory method to study various magnetic orders and their effects on the electronic structures of the FeSe. Our calculated results show that, for the spins of the single Fe layer, the striped antiferromagnetic orders with distortion are more favorable in total energy than the checkerboard antiferromagnetic orders with tetragonal symmetry, which is consistent with known experimental data, and the inter-layer magnetic interaction is very weak. We investigate the electronic structures and magnetic property of the distorted phases. We also present our calculated spin coupling constants and discuss the reduction of the Fe magnetic moment by quantum many-body effects. These results are useful to understand the structural, magnetic, and electronic properties of FeSe, and may have some helpful implications to other FeAs-based materials.