Ce基重费米子材料中4f电子特性研究

重费米子是强关联电子体系中最典型的代表之一，自发现以来一直备受研究者们的关注。重费米子材料中局域的f电子与巡游的导带电子之间的杂化导致了各种的奇异量子序和量子相变。各种新奇量子现象的出现，一方面对几十年来一直在固体物理领域占据统治地位的两个成功的经典理论，朗道费米液体理论和BSC理论，提出了挑战；另一方面，这些新的物理现象为新的科学突破提供了契机。重费米子研究有两个重要研究方向：理解非常规超导电性和理解量子相变和量子临界密切。重费米子中f电子的局域或巡游性质与这两个研究方向都密切相关。本项目拟从以Ce-基为代表的重费米子的电子结构入手，利用高分辨率的角分辨光电子能谱和超快光谱技术，并结合理论，详细研究其重准粒子色散和费米面拓扑结构随温度/掺杂的演化，可望阐明重费米子f电子局域-巡游转变微观过程和物理机制，为理解重费米子物理及非常规超导提供关键性证据。

Heavy fermions are one of the most typical representatives of strongly correlated electronic systems and have been attracting much attention from researchers since their discovery. The hybridization between local f electrons and traveling band electrons in heavy fermion materials leads to various exotic quantum orders and quantum phase transitions. On the one hand, the emergence of various novel quantum phenomena challenges two successful classical theories, Landau Fermi liquid theory and BSC theory, which have dominated the field of solid physics for decades. On the other hand, these new physical phenomena provide opportunities for new scientific breakthroughs. There are two important research directions for the heavy Fermion: understanding unconventional superconductivity, and understanding quantum phase transition and quantum criticality. The local or itinerant properties of f electrons in heavy fermions are closely related to these two directions. This project intends to study the electronic structures of Ce-based heavy Fermions, using high-resolution angle-resolved photoemission spectroscopy and ultrafast spectroscopy. Combining with theory, study the temperature and doping evolution of the heavy quasiparticles and the fermion surface topological structure. It is expected to elucidate the microscopic processes and physical mechanisms of the local-itinerant transition of f electrons, and to provide key evidence for the understanding of heavy fermion physics and unconventional superconductivity.