NSRRC Activity Report 2023

010 NSRRC ACTIVITY REPORT 2023 combined experimental and theoretical approaches provide a comprehensive understanding of the electronic and magnetic properties of FeTe, highlighting the significance of the Kondo effect and its impact on the material’s behavior. This work provides a comprehensive understanding of the electronic and magnetic properties of FeTe, a material that has been the subject of intense research because of its unique properties and potential applications in superconductivity and spintronics. The study combines various experimental techniques, including ARPES, STS, and transport measurements, to reveal the interplay between Kondo hybridization and long-range magnetic order in FeTe and provide evidence for the emergence of Kondo lattice behavior. The study also provides insights into the origin of the anomalous Hall effect and the role of band inversion and topology in the bulk electronic structure of FeTe, shedding light on the interplay between spin and electronic degrees of freedom in correlated d -electron multiorbital systems. Overall, the study highlights the significance of the Kondo effect and heavy fermion states in FeTe. This may have implications for the development of new materials with unique electronic and magnetic properties. (Reported by Ping-Hui Lin) This report features the work of Soonsang Huh, Changyoung Kim and their collaborators published in Nat. Comm. 14 , 4145 (2023). TLS 21B1 Angle-resolved UPS • ARPES • Kondo Lattice Behavior, FeTe, ARPES, Heavy Fermion Reference 1. Y. Kim, M.-S. Kim, D. Kim, M. Kim, M. Kim, C.-M. Cheng, J. Choi, S. Jung, D. Lu, J. H. Kim, S. Cho, D. Song, D. Oh, L. Yu, Y. J. Choi, H.-D. Kim, J. H. Han, Y. Jo, J. H. Shim, J. Seo, S. Huh, C. Kim, Nat. Comm. 14 , 4145 (2023). Fig. 2 : (a) Fermi surface maps from high resolution laser ARPES measurements, obtained at 15 and 80 K. (b) Temperature dependent high symmetry cuts along the Γ’-X’ direction. ARPES data were taken with 11 eV photons. (c) Energy distribution curves (EDCs) integrated within a certain momentum range ( k x 2 + k y 2 < (0.15 Å −1 ) 2 ). The EDCs are normalized with the integrated intensity from an energy window of −0.25 eV < −0.2 eV. (d) Symmetrized EDCs of (c). Inset: enlarged view of EDCs near the Fermi level. (e) Temperature-dependent spectral weight at E = E F and E = E F – 0.1 eV. (f,g) Temperature-dependent Fermi momentum ( k F ) and Fermi velocity ( v F ), respectively, obtained from momentum distribution curve analysis. [Reproduced from Ref. 1]