Ce 基重费米子材料的电子态研究与维度调控

重费米子材料作为一类典型的强关联电子体系，蕴含着非常规超导、奇异金属、量子临界、 磁有序、重电子态、关联拓扑态等新奇的量子态，而4f 电子在其中扮演着重要的作用。随着高分 辨角分辨光电子能谱和薄膜生长技术的发展，精确探测重费米子材料中4f 电子在能量/动量空间 的色散和谱权重成为了可能，这为从微观上理解这类材料中的电子关联效应和新奇量子现象提供 了重要的基础。本论文总结了几个典型的重费米子单晶和薄膜体系的电子态研究，包括Ce-115 体 系、CeCu2Si2、CeRh6Ge4 以及单晶 Ce 膜等。这些结果为理解重费米子体系中重电子态的形成 和温度演化、近藤杂化的能带/动量依赖、重电子能带与超导的关系、近藤效应与磁性和其它量子 态的竞争、4f 电子的维度调控等重要物理问题提供了谱学证据。

Probing the Electronic Structure and Dimensionality Tuning of Ce-Based Heavy Fermion Materials

Heavy fermion compound is a classical type of correlated materials, encompassing unconventional superconductivity, strange metal, quantum criticality, magnetic order, heavy electronic states, correlated topological states, etc, in which 4f electrons play a critical role. With the advancement of high-resolution ARPES measurements and MBE thin film growth techniques, direct observation of the band dispersion and spectral weight of 4f electrons in momentum/energy space has become possible, providing spectroscopic insight for understanding correlated electronic states and novel quantum phenomena. In this review paper, we summarized the electronic studies of several typical heavy fermion compounds and thin films, including Ce-115 families, CuCu2Si2, CeRh6Ge4 and Ce films, etc. The experimental results provide direct evidence to understand the temperature evolution of heavy electronic states, energy/moment-dependent Kondo hybridization, the interplay of heavy electronic state with superconductivity, the competition between Kondo effect with other quantum states and the dimensionality tuning of 4f electrons.