Strongly Entangled Kondo and Kagome Lattices and the Emergent Magnetic Ground State in Heavy-Fermion Kagome Metal YbV$_6$Sn$_6$
Rui Lou, Max Mende, Riccardo Vocaturo, Hao Zhang, Qingxin Dong, Man Li, Pengfei Ding, Erjian Cheng, Zhiguang Liao, Yu Zhang, Junfa Lin, Reza Firouzmandi, Vilmos Kocsis, Laura T. Corredor, Yurii Prots, Oleksandr Suvorov, Anupam Jana, Jun Fujii, Ivana Vobornik, Oleg Janson, Wenliang Zhu, Jeroen van den Brink, Cornelius Krellner, Minghu Pan, Bosen Wang, Tianlong Xia, Jinguang Cheng, Shancai Wang, Claudia Felser, Bernd Büchner, Sergey Borisenko, Rong Yu, Denis V. Vyalikh, Alexander Fedorov
公開日: 2025/9/4
Abstract
Applying angle-resolved photoemission spectroscopy and density functional theory calculations, we present compelling spectroscopic evidence demonstrating the intertwining and mutual interaction between the Kondo and kagome sublattices in heavy-fermion intermetallic compound YbV$_6$Sn$_6$. We reveal the Yb 4$f$-derived states near the Fermi level, along with the presence of bulk kagome bands and topological surface states. We unveil strong interactions between the 4$f$ and itinerant electrons, where the kagome bands hosting the Dirac fermions and van Hove singularities predominate. Such findings are well described using a $c$-$f$ hybridization model. On the other hand, our systematic characterization of magnetic properties demonstrates an unusually enhanced antiferromagnetic ordering, where the kagome-derived van Hove singularities near $E_F$ play a vital role in determining the unconventional nature of the Ruderman-Kittel-Kasuya-Yosida interaction and Kondo coupling. These unique kagome-state-mediated exchange interactions have never been reported before and could lead to a novel phase diagram and various quantum critical behaviors in YbV$_6$Sn$_6$ and its siblings. Our results not only expand the family of exotic quantum phases entangled with kagome structure to the strongly correlated regime, but also establish YbV$_6$Sn$_6$ as an unprecedented platform to explore unconventional many-body physics beyond the standard Kondo picture.