摘要
High-temperature superconductivity(HTSC)remains one of the most challenging and fascinating mysteries in condensed matter physics.Recently,superconductivity with transition temperature exceeding liquid-nitrogen temperature is discovered in La_(3)Ni_(2)O_(7) at high pressure,which provides a new platform to explore the unconventional HTSC.In this work,using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation,we systematically investigate the electronic structures of La_(3)Ni_(2)O_(7) at ambient pressure.Our experiments are in nice agreement with ab initio calculations after considering an orbital-dependent band renormalization effect.The strong electron correlation effect pushes a flat band of d_(z^(2))𝑧2 orbital component below the Fermi level(E_(F)),which is predicted to locate right at E_(F) under high pressure.Moreover,the d_(x^(2)−y^(2)) band shows pseudogap-like behavior with suppressed spectral weight and diminished quasiparticle peak near E_(F).Our findings provide important insights into the electronic structure of La_(3)Ni_(2)O_(7),which will shed light on understanding of the unconventional superconductivity in nickelates.
作者
Yidian Li
Xian Du
Yantao Cao
Cuiying Pei
Mingxin Zhang
Wenxuan Zhao
Kaiyi Zhai
Runzhe Xu
Zhongkai Liu
Zhiwei Li
Jinkui Zhao
Gang Li
Yanpeng Qi
Hanjie Guo
Yulin Chen
Lexian Yang
李义典;杜宪;曹延涛;裴翠颖;张明鑫;赵文轩;翟恺熠;许润哲;柳仲楷;李志伟;赵金奎;李刚;齐彦鹏;郭汉杰;陈宇林;杨乐仙(State Key Laboratory of Low Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China;Key Lab for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University,Lanzhou 730000,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;ShanghaiTech Laboratory for Topological Physics,Shanghai 200031,China;Shanghai Key Laboratory of High-Resolution Electron Microscopy,ShanghaiTech University,Shanghai 201210,China;Department of Physics,Clarendon Laboratory,University of Oxford,Parks Road,Oxford OX13PU,UK;Frontier Science Center for Quantum Information,Beijing 100084,China)
基金
supported by the National Key R&D Program of China(Grant Nos.2022YFA1403100 and 2022YFA1403200)
the National Natural Science Foundation of China(Grant Nos.12275148,12004270,and 52272265)
Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515120020)
support from Tsinghua University Initiative Scientific Research Program.
