Enhanced - hybridization intertwined with anomalous ground state formation in the van der Waals itinerant magnet FeGeTe

ファンデルワールス結合磁性金属FeGeTeにおける異常な基底状態形成と絡み合って増強された-混成軌道

山神 光平*; 藤澤 唯太*; Pardo-Almanza, M*; Smith, B. R. M.*; 角田 一樹   ; 竹田 幸治   ; 岡田 佳憲*

Yamagami, Kohei*; Fujisawa, Yuita*; Pardo-Almanza, M*; Smith, B. R. M.*; Sumida, Kazuki; Takeda, Yukiharu; Okada, Yoshinori*

FeGeTe is a van der Waals (vdW) coupled unconventional ferromagnetic metal with a high Curie temperature (), exceeding 300 K. The formation of an anomalous ground state far below has attracted great interest, leading to a need to understand the spin-polarized electronic state near the Fermi energy () at low temperature. Despite recent extensive study, a microscopic understanding of the spin polarized electronic structure around has not been established yet due to the intrinsic complexity of both the crystal and band structures. In this work, we investigate the temperature dependence of element-specific soft X-ray magnetic circular dichroism (XMCD). Systematic temperature evolution in the XMCD signal from both magnetic Fe and its ligand Te is clearly observed. Importantly, the enhancement of the hybridization between Fe 3 and Te 5 states in the zero-magnetic field limit has been revealed. In light of the possible emergence of an exotic ground state, we discuss the temperature and magnetic field evolution of the element specific XMCD results.