Department of Physics , Pusan National University , Busan 46241 , Korea.
Max Planck-POSTECH/Hsinchu Center for Complex Phase Materials , Pohang University of Science and Technology , Pohang 37673 , Korea.
Nano Lett. 2018 Jun 13;18(6):3661-3666. doi: 10.1021/acs.nanolett.8b00784. Epub 2018 May 21.
The interaction between a magnetic impurity, such as cerium (Ce) atom, and surrounding electrons has been one of the core problems in understanding many-body interaction in solid and its relation to magnetism. Kondo effect, the formation of a new resonant ground state with quenched magnetic moment, provides a general framework to describe many-body interaction in the presence of magnetic impurity. In this Letter, a combined study of angle-resolved photoemission (ARPES) and dynamic mean-field theory (DMFT) on Ce-intercalated graphene shows that Ce-induced localized states near Fermi energy, E, hybridized with the graphene π-band, exhibit gradual increase in spectral weight upon decreasing temperature. The observed temperature dependence follows the expectations from the Kondo picture in the weak coupling limit. Our results provide a novel insight how Kondo physics emerges in the sea of two-dimensional Dirac electrons.
磁性杂质（如铈（Ce）原子）与周围电子之间的相互作用一直是理解固体中多体相互作用及其与磁性关系的核心问题之一。Kondo 效应，即形成具有淬灭磁矩的新共振基态，为描述存在磁性杂质时的多体相互作用提供了一个通用框架。在这封信中，对插层石墨烯的角分辨光电子能谱（ARPES）和动态平均场理论（DMFT）的联合研究表明，Ce 诱导的近费米能局域态与石墨烯的π带杂化，在温度降低时表现出光谱权重的逐渐增加。观察到的温度依赖性符合弱耦合极限下 Kondo 图像的预期。我们的结果提供了一个新的视角，说明 Kondo 物理如何在二维狄拉克电子的海洋中出现。
