2021/03/31 by Hiroki Nakai, Chisa Hotta
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Coulomb #Degenerate energy levels #Electron #Electronic and Structural Properties of Oxides #Physics #Quantum mechanics #Spin (aerodynamics) #Spin–orbit interaction #Topological Materials and Phenomena #Topological insulator #Wave function #cond-mat.str-el
paper · pdf · doi:10.1038/s41467-022-28132-y
11pages, 7 figures
arxiv created 2021/09/17 · openalex publication_date 2022/02/01 · arxiv updated 2022/02/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract Spin-orbit interaction has established itself as a key player in the emergent phenomena in modern condensed matter, including topological insulator, spin liquid and spin-dependent transports. However, its function is rather limited to adding topological nature to band kinetics, leaving behind the growing interest in the direct interplay with electron correlation. Here, we prove by our spinor line graph theory that a very strong spin-orbit interaction realized in 5 d pyrochlore electronic systems generates multiply degenerate perfect flat bands. Unlike any of the previous flat bands, the electrons in this band localize in real space by destructively interfering with each other in a spin selective manner governed by the SU(2) gauge field. These electrons avoid the Coulomb interaction by self-organizing their localized wave functions, which may lead to a flat-band state with a stiff spin chirality. It also causes perfectly trimerized charge ordering, which may explain the recently discovered exotic low-temperature insulating phase of CsW 2 O 6 .