2013/12/12 by Chul-Hee Min, P. Lutz, Sebastian Fiedler +9 · 6 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Charge (physics) #Phase (matter) #Physics #Quantum mechanics #Rare-earth and actinide compounds #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.112.226402
published as Phys. Rev. Lett. 112, 226402 (2014) · 12 pages, 5 figures
arxiv created 2013/12/12 · openalex publication_date 2014/06/05 · arxiv updated 2014/06/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Typical Kondo insulators (KIs) can have a nontrivial Z2 topology because the energy gap opens at the Fermi energy (EF) by a hybridization between odd- and even-parity bands. SmB6 deviates from such KI behavior, and it has been unclear how the insulating phase occurs. Here, we demonstrate that charge fluctuations are the origin of the topological insulating phase in SmB6. Our angle-resolved photoemission spectroscopy results reveal that with decreasing temperature the bottom of the d-f hybridized band at the X[over ¯] point, which is predicted to have odd parity and is required for a topological phase, gradually shifts from below to above EF. We conclude that SmB6 is a charge-fluctuating topological insulator.