Two-dimensional(2D)honeycomb-like materials have been widely studied due to their fascinating properties.In particular,2D honeycomb-like transition metal monolayers,which are good 2D ferromagnet candidates,have attrac...Two-dimensional(2D)honeycomb-like materials have been widely studied due to their fascinating properties.In particular,2D honeycomb-like transition metal monolayers,which are good 2D ferromagnet candidates,have attracted intense research interest.The honeycomb-like structure of hafnium,hafnene,has been successfully fabricated on the Ir(111)substrate.However,its electronic structure has not yet been directly elucidated.Here,we report the electronic structure of hafnene grown on the Ir(111)substrate using angle-resolved photoemission spectroscopy(ARPES).Our results indicate that the presence of spin-orbit coupling and Hubbard interaction suppresses the earlier predicted Dirac cones at the K points of the Brillouin zone.The observed band structure of hafnene near the Fermi level is very simple:an electron pocket centered at theΓpoint of the Brillouin zone.This electron pocket shows typical parabolic dispersion,and its estimated electron effective mass and electron density are approximately 1.8_(me)and 7×10^(14)cm^(-2),respectively.Our results demonstrate the existence of 2D electron gas in hafnene grown on the Ir(111)substrate and therefore provide key information for potential hafnene-based device applications.展开更多
基金This work is supported by the National Key Research and Development Program of China(Nos.2017YFA0303600 and 2020YFA0308800)the National Natural Science Foundation of China(Nos.11974364,11674367,U2032207,92163206,11974045,and 61725107)+2 种基金the Natural Science Foundation of Zhejiang,China(No.LZ18A040002)the Ningbo Science and Technology Bureau(No.2018B10060)S.L.H.would like also to acknowledge the Ningbo 3315 program.
文摘Two-dimensional(2D)honeycomb-like materials have been widely studied due to their fascinating properties.In particular,2D honeycomb-like transition metal monolayers,which are good 2D ferromagnet candidates,have attracted intense research interest.The honeycomb-like structure of hafnium,hafnene,has been successfully fabricated on the Ir(111)substrate.However,its electronic structure has not yet been directly elucidated.Here,we report the electronic structure of hafnene grown on the Ir(111)substrate using angle-resolved photoemission spectroscopy(ARPES).Our results indicate that the presence of spin-orbit coupling and Hubbard interaction suppresses the earlier predicted Dirac cones at the K points of the Brillouin zone.The observed band structure of hafnene near the Fermi level is very simple:an electron pocket centered at theΓpoint of the Brillouin zone.This electron pocket shows typical parabolic dispersion,and its estimated electron effective mass and electron density are approximately 1.8_(me)and 7×10^(14)cm^(-2),respectively.Our results demonstrate the existence of 2D electron gas in hafnene grown on the Ir(111)substrate and therefore provide key information for potential hafnene-based device applications.
