Electronic Structure of Superconducting Infinite-Layer Lanthanum Nickelates

• DOI: 10.48550/arxiv.2403.07344
• Publication Date: 2024-03-12
• Authors: Wenjie Sun; Zhicheng Jiang; Chengliang Xia; Bo Hao; Yueying Li; Shengjun Yan; Maosen Wang; Hongquan Liu; Jianyang Ding; Jiayu Liu; Zhengtai Liu; Jishan Liu; Hanghui Chen; Dawei Shen; Yuefeng Nie
• Keywords: Lanthanum

Revealing the momentum-resolved electronic structure of infinite-layer nickelates is essential for understanding this new class unconventional superconductors, but has been hindered by formidable challenges in improving sample quality. In work, we report first time angle-resolved photoemission spectroscopy superconducting La$_{0.8}$Sr$_{0.2}$NiO$_{2}$ films prepared molecular beam epitaxy and ${\mathrm{\textit{in situ}}}$ atomic-hydrogen reduction. The measured Fermi topology closely matches theoretical calculations, showing a large Ni-$d_{x^2-y^2}$ derived sheet that evolves from hole-like to electron-like along $k_{z}$, three-dimensional (3D) electron pocket centered at Brillouin zone corner. bands show mass enhancement ($m^*/m_{\rm{DFT}}$) 2-3,while 3D band shows negligible renormalization. Moreover, states also display dispersion anomaly higher binding energy, reminiscent waterfall feature kinks observed cuprates.