Direct Evidence for the Existence of Heavy Quasiparticles in the Magnetically Ordered Phase of CeRhIn^sub 5

• Published in: Journal of the Physical Society of Japan 2019-01, Vol.88 (1), p.1
• Main Authors: Haze, Masahiro, Peters, Robert, Torii, Yohei, Suematsu, Tomoka, Sano, Daiki, Naritsuka, Masahiro, Kasahara, Yuichi, Shibauchi, Takasada, Terashima, Takahito, Matsuda, Yuji
• Format: Article
• Language: English
• Subjects: Antiferromagnetism; Banded structure; Conduction bands; Crystal structure; Electric fields; Electronic structure; Electrons; Energy gap; Fermi surfaces; Fermions; Magnetism; Phase transitions; Resistance; Thin films
• ISSN: 0031-9015; 1347-4073
• DOI: 10.7566/JPSJ.88.014706

It is a long-standing important issue in heavy fermion physics whether f-electrons are itinerant or localized when the magnetic order occurs. Here we report the in situ scanning tunneling microscopy observation of the electronic structure in epitaxial thin films of CeRhIn5, a prototypical heavy fermion compound with antiferromagnetic ground state. The conductance spectra above the Néel temperature TN clearly resolve the energy gap due to the hybridization between local 4f electrons and conduction bands as well as the crystal electric field excitations. These structures persist even below TN. Moreover, an additional dip in the conductance spectra develops due to the antiferromagnetic order. These results provide direct evidence for the presence of itinerant heavy f-electrons participating in the Fermi surface even in the magnetically ordered state of CeRhIn5.