Kondo Holes in the Two-Dimensional Itinerant Ising Ferromagnet Fe<sub>3</sub>GeTe<sub>2</sub>.

Zhao, Mengting; Chen, Bin-Bin; Xi, Yilian; Zhao, Yanyan; Xu, Hang; Zhang, Hongrun; Cheng, Ningyan; Feng, Haifeng et al. · Nano Lett · 2021

basic_science · Level V

Where this comes from

Abstract

Heavy Fermion (HF) states emerge in correlated quantum materials due to the intriguing interplay between localized magnetic moments and itinerant electrons but rarely appear in 3d-electron systems due to high itinerancy of d-electrons. Here, an anomalous enhancement of Kondo screening is observed at the Kondo hole of local Fe vacancies in Fe<sub>3</sub>GeTe<sub>2</sub> which is a recently discovered 3d-HF system featuring Kondo lattice and two-dimensional itinerant ferromagnetism. An itinerant Kondo-Ising model is established to reproduce the experimental results and provides insight into the competition between Ising ferromagnetism and Kondo screening. Our work explains the microscopic origin of the d-electron HF states in Fe<sub>3</sub>GeTe<sub>2</sub> and inspires future studies of the enriched quantum many-body effects with Kondo holes.