English

Emerging kinetic-exchange for the enhanced metallic ferromagnetism in CrGeTe$_3$ under pressure

Strongly Correlated Electrons 2025-07-15 v1 Materials Science

Abstract

The microscopic origin of ferromagnetism in correlated materials remains heavily debated, particularly for the competing mechanisms governing insulating versus metallic phases. In this work, we theoretically study the electronic structure evolution of CrGeTe3_{3} under pressure and provide a consistent explanation to three unique features of this system, i.e. the semiconducting ferromagnetism at low pressure, the metallic ferromagnetism at high pressure, and the enhanced Curie temperature in the metallic phase. We propose that it is the reduced electronic correlation and enhanced dd-pp hybridization that universally drive the continuous evolution of CrGeTe3_{3} under pressure and glue the three distinct experimental observations. Central to our discovery is the dual role of metallicity -- it simultaneously establishes kinetically driven exchange via dd-pp hybridization and enables Stoner-type magnetic instability, with the contribution also from the residual super-exchange. Our analyses reveal that {\it intraband} excitations dominate the pressure-enhanced ωp2\omega_p^2 and TcT_c correlation. These findings establish dd-pp hybridization and electronic correlation as the bridge between localized and itinerant magnetism, at least, in CrGeTe3_{3}.

Keywords

Cite

@article{arxiv.2507.09877,
  title  = {Emerging kinetic-exchange for the enhanced metallic ferromagnetism in CrGeTe$_3$ under pressure},
  author = {Jiaming Liu and Xuefeng Zhang and Hongbin Qu and Xiaoqun Wang and Hai-Qing Lin and Gang Li},
  journal= {arXiv preprint arXiv:2507.09877},
  year   = {2025}
}

Comments

main text with 6 pages and 4 figures. Supplementary Information is included with 9 pages and 6 figures