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arXiv · 2510.02697

Spectroscopic evidence of Kondo resonance in 3$d$ van der Waals ferromagnets

Deepali Sharma·Neeraj Bhatt·Asif Ali·Rajeswari Roy Chowdhury·Chandan Patra·Ravi Prakash Singh·Ravi Shankar Singh
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Abstract

Two-dimensional van der Waals (vdW) ferromagnets drive the advancement in spintronic applications and enable the exploration of exotic magnetism in low-dimensional systems. The entanglement of dual $-$ localized and itinerant $-$ nature of electrons lies at the heart of the correlated electron systems giving rise to exotic ground state properties such as complex magnetism, heavy fermionic behavior, Kondo lattice formation, \textit{etc}. Through temperature-dependent electronic structure of vdW ferromagnets, (Co$_{x}$Fe$_{1-x}$)$_{3}$GeTe$_{2}$, probed using high-resolution photoemission spectroscopy and density functional theory combined with dynamical mean field theory (DFT+DMFT), we provide direct evidence of the emergence of Kondo resonance peak driven by complex interplay between localized and itinerant electrons. In overall agreement with experimental electronic structure and magnetic properties, DFT+DMFT also reveals finite spin band splitting well beyond $T_{C}$. Core levels, valence band photoemission spectra together with DFT+DMFT spectral functions reveal insignificant change across $T_{C}$ indicating non-Stoner magnetism in (Co$_{x}$Fe$_{1-x}$)$_{3}$GeTe$_{2}$. Our results provide a way forward to the understanding of complex interplay between electronic structure, exotic magnetism and heavy fermionic behavior leading to Kondo scenerio in 3$d$ vdW ferromagnets.

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Deepali Sharma, Neeraj Bhatt, Asif Ali, Rajeswari Roy Chowdhury, Chandan Patra, Ravi Prakash Singh, Ravi Shankar Singh. 2025-10-03. Spectroscopic evidence of Kondo resonance in 3$d$ van der Waals ferromagnets. https://arxiv.org/abs/2510.02697

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