重费米子化合物是研究关联电子体系中奇异量子态的经典体系，如重电子态、超导和多极矩轨道序。如何利用点接触隧道谱探测重费米子体系的不同量子态是一个重要的物理问题，可拓展点接触谱研究的内涵。首先，通过推广的BTK模型拟合，点接触隧道谱为探索重费米子超导态的能隙和序参量对称性提供重要线索。其次，重电子态起源于局域f电子和巡游导带电子之间的相干杂化，其点接触隧道谱曲线会呈现Fano或杂化能隙的结构。最后，重费米子化合物的多极矩轨道序会引起费米能级附近态密度的变化，利用点接触谱探测轨道波能隙也是有趣的研究课题。在本项目中，我们计划以若干重费米子化合物为研究对象，比如CeCu2Si2, PrOs4Sb12, PrFe4P12和CeB6，通过针尖型机械点接触谱和(压力下)银胶型软点接触谱的比较实验，探索重费米子中不同量子态对点接触隧道谱的影响，研究强关联电子体系的新奇量子态及其调控的一般规律。

Heavy fermions are a prototype to study exotic quantum states in strongly correlated electron systems, such as heavy electron state, superconductivity and multipole orbital ordering, while point-contact spectroscopy (PCS) serves as a powerful tool to study these quantum states and is of great interest in the community. Firstly, PCS measurements on heavy fermion superconductor provide important clues on its superconducting gap and order parameter symmetry with extended Blonder-Tinkham-Klapwijk model. Secondly, heavy electrons in heavy fermions originate from the coherent hybridization between local f and itinerant conduction electrons. A Fano or hybridization gap structure is present in the point-contact spectra, mimicking the enhanced hybridization with reduced temperature. Lastly, the multipole orbital ordering in heavy fermions will open a gap with modified density of states around Fermi energy, which should be susceptible to PCS. In this project, various quantum states in heavy fermion compounds CeCu2Si2, PrOs4Sb12, PrFe4P12 and CeB6 will be our proposed focus, where needle-anvil type mechanical PCS and silver epoxy type soft PCS are planned for comparative studies with the possibility to extend soft PCS under pressure if necessary. PCS investigations on various quantum states in heavy fermions will deepen our general understanding on exotic quantum state and its manipulation in strongly correlated electron systems.