Cuprate-like electronic structures in infinite-layer nickelates with substantial hole dopings  

作　　者：Xiang Ding Yu Fan Xiaoxiao Wang Chihao Li Zhitong An Jiahao Ye Shenglin Tang Minyinan Lei Xingtian Su Nan Guo Zhihui Chen Suppanut Sangpht lin Wang Haichao Xu Rui Peng Donglai feng 

机构地区：[1]Advanced Materials Laboratory,State Key Laboratory of Surface Physics,and Department of Physics,Fudan University,Shanghai 200433,China [2]School of Emerging Technology,University of Science and Technology of China,Hefei 230026,China [3]New Cornerstone Science Laboratory,University of Science and Technology of China,Hefei 230026,China [4]Shanghai Research Center for Quantum Sciences,Shanghai 201315,China [5]National Synchrotron Radiation Laboratory and School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230026,China

出　　处：《National Science Review》2024年第8期174-180,共7页国家科学评论（英文版）

基　　金：supported in part by the National Natural Science Foundation of China (12074074,12274085 and 12174365);the National Key R&D Program of the Ministry of Science and Technology (MOST)of China (2023YFA1406300);the New Cornerstone Science Foundation,the Innovation Program for Quantum Science and Technology (2021ZD0302803);the Shanghai Municipal Science and Technology Major Project (2019SHZDZX01);the China National Postdoctoral Program for Innovative Talents (BX20230078);Part of this research used Beamline 03U of the Shanghai Synchrotron Radiation Facility,which is supported by the ME2 project (11227902)from the National Natural Science Foundation of China.

摘　　要：Superconducting infinite-layer(IL)nickelates offer a new platform for investigating the long-standing problem of high-temperature superconductivity.Many models were proposed to understand the superconducting mechanism of nickelates based on the calculated electronic structure,and the multiple Fermi surfaces and multiple orbitals involved create complications and controversial conclusions.Over the past five years,the lack of direct measurements of the electronic structure has hindered the understanding of nickelate superconductors.Here we fillthis gap by directly resolving the electronic structures of the parent compound LaNiO_(2) and superconducting La_(0.8)Ca_(0.2)NiO_(2) using angle-resolved photoemission spectroscopy.We find that their Fermi surfaces consist of a quasi-2D hole pocket and a 3D electron pocket at the Brillouin zone corner,whose volumes change upon Ca doping.The Fermi surface topology and band dispersion of the hole pocket closely resemble those observed in hole-doped cuprates.However,the cuprate-like band exhibits significantly higher hole doping in superconducting La_(0.8)Ca_(0.2) NiO_(2) compared to superconducting cuprates,highlighting the disparities in the electronic states of the superconducting phase.Our observations highlight the novel aspects of the IL nickelates,and pave the way toward the microscopic understanding of the IL nickelate family and its superconductivity.

关 键 词：unconventional superconductivity nickelate superconductors oxide MBE ARPES electronic structure superconducting phase diagram 

分 类 号：O52[理学—高压高温物理]