2026-10-06 大阪大学
図1. YbCu2とCuの間を伝播する界面重い電子の概念図
＜関連情報＞
- https://www.fbs.osaka-u.ac.jp/ja/research_results/papers/detail/1125
- https://www.nature.com/articles/s43246-026-01332-5
Cu(111)基板上の二次元近藤格子YbCu2における界面重フェルミオン形成 Interfacial heavy fermion formation in a two-dimensional Kondo lattice YbCu2 on Cu(111) substrate
Takuto Nakamura, Hiroki Sugihara, Toshio Miyamachi, Yitong Chen, Kaito Nishihara, Ryo Ichikawa, Hiroka Yamaguchi, Ryu Yukawa, Kiyohisa Tanaka, Yuri Hasegawa, Yoshiyuki Ohtsubo, Fumio Komori & Shin-ichi Kimura
Communications Materials Published:06 October 2026
DOI:https://doi.org/10.1038/s43246-026-01332-5
Abstract
The exchange interaction between a local magnetic moment and itinerant carriers mediated by the Kondo effect is the origin of strongly correlated quantum phenomena. The concept of an interfacial Kondo lattice, exemplified by the moiré Kondo lattice, provides a powerful platform for exploring quantum critical phenomena such as non-Fermi-liquid behavior and unconventional superconductivity in low dimensions, owing to the high tunability and sensitivity of its physical parameters. However, direct observation of interfacial heavy fermions (HF) has remained elusive due to the lack of suitable candidate systems. Here, we present momentum-resolved evidence of interfacial HF formation between a rare-earth-based two-dimensional (2D) Kondo lattice, YbCu2, and a noble-metal Cu(111) substrate, obtained using high-resolution synchrotron-based angle-resolved photoemission spectroscopy. Momentum-resolved measurements unambiguously reveal interfacial HF states arising from hybridization between the Cu(111) metallic band and the Yb 4f orbitals in the topmost YbCu2 layer. Our experimental results establish an alternative degree of freedom for fabricating artificial Kondo lattices in low-dimensional systems.
