2021/03/01 by Cheng Hu, Jianfa Zhao, Qiang Gao +13 · 29 citations
Chemistry · Materials Science · Physics and Astronomy · #Band gap #Cuprate #Doping #Electron #Electronic and Structural Properties of Oxides #Inorganic Fluorides and Related Compounds #Metal–insulator transition #Mott insulator #Mott transition #Physics of Superconductivity and Magnetism #Superconductivity #cond-mat.mtrl-sci #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1038/s41467-021-21605-6
published in Nature Communications 12(1), 1356 (Nature Portfolio) · 23 pages, 5 figures
arxiv created 2021/03/01 · openalex publication_date 2021/03/01 · arxiv updated 2021/03/03 · openalex created_date 2021/03/15 · openalex updated_date 2026/08/05
High temperature superconductivity in cuprates arises from doping a parent Mott insulator by electrons or holes. A central issue is how the Mott gap evolves and the low-energy states emerge with doping. Here we report angle-resolved photoemission spectroscopy measurements on a cuprate parent compound by sequential in situ electron doping. The chemical potential jumps to the bottom of the upper Hubbard band upon a slight electron doping, making it possible to directly visualize the charge transfer band and the full Mott gap region. With increasing doping, the Mott gap rapidly collapses due to the spectral weight transfer from the charge transfer band to the gapped region and the induced low-energy states emerge in a wide energy range inside the Mott gap. These results provide key information on the electronic evolution in doping a Mott insulator and establish a basis for developing microscopic theories for cuprate superconductivity.