Visualizing the atomic-scale origin of metallic behavior in Kondo insulators

• 成果类型: Article
• 署名作者: Pirie, Harris; Mascot, Eric; Matt, Christian E.; Liu, Yu; Chen, Pengcheng; Hamidian, M. H.; Saha, Shanta; Wang, Xiangfeng; Paglione, Johnpierre; Luke, Graeme; Goldhaber-Gordon, David; Hirjibehedin, Cyrus F.; Davis, J. C. Seamus; Morr, Dirk K.; Hoffman, Jennifer E.
• 署名单位: Harvard University; University of Oxford; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University System of Maryland; University of Maryland College Park; McMaster University; Stanford University; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; University of London; University College London; University of London; University College London; University of London; University College London; University College Cork; Cornell University; Max Planck Society; Massachusetts Institute of Technology (MIT); Lincoln Laboratory
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-14117
• DOI: 10.1126/science.abq5375
• 发表日期: 2023-03-24
• 页码: 1214-+
• 关键词: hidden-order transition; fermi-surface; STATES; smb6; superconductivity; instability; lattice; holes

摘要

A Kondo lattice is often electrically insulating at low temperatures. However, several recent experiments have detected signatures of bulk metallicity within this Kondo insulating phase. In this study, we visualized the real-space charge landscape within a Kondo lattice with atomic resolution using a scanning tunneling microscope. We discovered nanometer-scale puddles of metallic conduction electrons centered around uranium-site substitutions in the heavy-fermion compound uranium ruthenium silicide (URu2Si2) and around samarium-site defects in the topological Kondo insulator samarium hexaboride (SmB6). These defects disturbed the Kondo screening cloud, leaving behind a fingerprint of the metallic parent state. Our results suggest that the three-dimensional quantum oscillations measured in SmB6 arise from Kondo-lattice defects, although we cannot exclude other explanations. Our imaging technique could enable the development of atomic-scale charge sensors using heavy-fermion probes.