A new class of bilayer kagome lattice compounds with Dirac nodal lines and pressure-induced superconductivity

Mengzhu Shi; Fanghang Yu; Ye Yang; Fanbao Meng; Bin Lei; Yang Luo; Zhe Sun; Junfeng He; Rui Wang; Zhicheng Jiang; Zhengtai Liu; Dawei Shen; Tao Wu; Zhenyu Wang; Ziji Xiang; Jianjun Ying; Xianhui Chen

doi:10.1038/s41467-022-30442-0

A new class of bilayer kagome lattice compounds with Dirac nodal lines and pressure-induced superconductivity

Nat Commun. 2022 May 19;13(1):2773. doi: 10.1038/s41467-022-30442-0.

Authors

Mengzhu Shi^#¹, Fanghang Yu^#¹, Ye Yang¹, Fanbao Meng¹, Bin Lei¹, Yang Luo¹, Zhe Sun², Junfeng He¹, Rui Wang³, Zhicheng Jiang⁴, Zhengtai Liu⁴, Dawei Shen⁴, Tao Wu^{1

5}, Zhenyu Wang^{1

5}, Ziji Xiang¹, Jianjun Ying^{6

7}, Xianhui Chen^{8

9

10

11}

Affiliations

¹ CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
² National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, China.
³ Institute for Structure and Function & Department of physics & Center for Quantum Materials and Devices, Chongqing University, Chongqing, 400044, China.
⁴ State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
⁵ CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, 200050, China.
⁶ CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China. yingjj@ustc.edu.cn.
⁷ CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, 200050, China. yingjj@ustc.edu.cn.
⁸ CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China. chenxh@ustc.edu.cn.
⁹ CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai, 200050, China. chenxh@ustc.edu.cn.
¹⁰ CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui, 230026, China. chenxh@ustc.edu.cn.
¹¹ Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China. chenxh@ustc.edu.cn.

^# Contributed equally.

Abstract

Kagome lattice composed of transition-metal ions provides a great opportunity to explore the intertwining between geometry, electronic orders and band topology. The discovery of multiple competing orders that connect intimately with the underlying topological band structure in nonmagnetic kagome metals AV₃Sb₅ (A = K, Rb, Cs) further pushes this topic to the quantum frontier. Here we report a new class of vanadium-based compounds with kagome bilayers, namely AV₆Sb₆ (A = K, Rb, Cs) and V₆Sb₄, which, together with AV₃Sb₅, compose a series of kagome compounds with a generic chemical formula (A_m-1Sb_2m)(V₃Sb)_n (m = 1, 2; n = 1, 2). Theoretical calculations combined with angle-resolved photoemission measurements reveal that these compounds feature Dirac nodal lines in close vicinity to the Fermi level. Pressure-induced superconductivity in AV₆Sb₆ further suggests promising emergent phenomena in these materials. The establishment of a new family of layered kagome materials paves the way for designer of fascinating kagome systems with diverse topological nontrivialities and collective ground states.