Abstract
In uranium-based heavy fermion systems, the electrons display an intermediate character between partial localization and partial itinerancy, which makes the Kondo problem more complicated. Here we use scanning tunneling microscopy/spectroscopy to investigate the (001) surface of the Kondo lattice antiferromagnet . Temperature-dependent spectra from 4.7 K up to 140 K reveal several peak structures around the Fermi level. Two pronounced peaks originate from the hybridization between the conduction and electrons. We did not observe the mysteriously abrupt change of the electronic state at 45 K, which was previously reported by another scanning tunneling microscopy group and attributed to a novel first-order-like transition. Instead, we only observe continuous evolution of the spectra with temperature. Furthermore, in some scanning regions, we find significant Sb atoms missing from the top layer, which gives us the opportunity to investigate the electronic structure of the U-terminated surface. For the U-terminated surface, an additional sharp peak emerges, which is closely related to the magnetic order.
- Received 29 September 2021
- Accepted 15 November 2021
DOI:https://doi.org/10.1103/PhysRevB.104.235103
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