Work

Understanding nematicity and band structure of FeSe by first-principles study and tight-binding model

Year: 2026

Type: article

Abstract: We systematically investigate the effects of spin order and orbital polarization on the electronic and magnetic structures of nematic FeSe using the LDA + U method. While our calculations with on-site Coulomb repulsion U ∼ 4.5 eV can account for both the nonmagnetic state at ambient pressure and the phase transition to a stripe antiferromagnetic state at moderate pressure as observed experimentally, neither static spin order nor static orbital polarization can describe the experimental band dispersions from angle-resolved photoemission spectroscopy (ARPES) studies, due to the underestimate of quantum fluctuations. By employing a particle swarm optimization algorithm, we construct a tight-binding model with inclusion of correlation effects through seeking appropriate renormalization factors of kinetic energies, which successfully reproduce the ARPES results at various temperatures, highlighting the importance of correlations in FeSe.

Source: Physical Review Research

DOI: 10.1103/tjzc-cbhr

Authors: Miao-Miao Li, Xiu-Cai Jiang, Yu-Zhong Zhang

Institution: Tongji University

Language: English

Topic: Iron-based superconductors research

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: Shanghai Science and Technology Development Foundation, National Natural Science Foundation of China