(Formula presented) study of two-dimensional heavy-fermion Ce(Formula presented) family (T[jls-end-space/]=C, Si, Ge; X[jls-end-space/]=Cl, Br, I)

초록

Recent discovery of the two-dimensional (2D) van der Waals (vdW) heavy-fermion material CeSiI has stimulated great interest in exploring heavy-fermion physics in the 2D limit. Here, we systematically investigate the heavy-fermion properties of the Ce(Formula presented) family (T[jls-end-space/]=C, Si, Ge; X[jls-end-space/]=Cl, Br, I) using dynamical mean-field theory combined with density functional theory (DFT+DMFT). Phonon calculations reveal that CeCX is structurally unstable, while CeSiX and CeGeX exhibit stable vdW layered structures. The CeSiCl and CeSiBr exhibit a stronger Kondo resonance state compared to CeSiI, whereas CeGeX shows suppressed Kondo resonance states due to the increased Ce–Ce distance. Although the constructed phase diagram demonstrates that CeSiX series lies in the magnetically ordered region, CeSiBr approaches the boundary between magnetic and paramagnetic heavy-fermion phases, suggesting its tunability under external perturbations. Our results establish the CeSiX series as a prototypical platform for realizing and understanding 2D vdW heavy-fermion systems. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

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