Discovery of Two Families of Vsb-Based Compounds with V-Kagome Lattice
Yuxin Yang, Wenhui Fan, Qinghua Zhang, Zhao‐Xu Chen, Chen Xu, Tianping Ying, Xianxin Wu, Xiaofan Yang, Fanqi Meng, Gang Li, Shiyan Li, Lin Gu, Tian Qian, Andreas P. Schnyder, Jiangang Guo, Xiaolong Chen
Abstract
We report the structure and physical properties of two newly discovered compounds AV 8 Sb 12 and AV 6 Sb 6 (A = Cs, Rb), which have C 2 (space group: Cmmm ) and C 3 (space group: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>R</mml:mi> <mml:mover accent="true"> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> <mml:mrow> <mml:mo stretchy="false">¯</mml:mo> </mml:mrow> </mml:mover> <mml:mi>m</mml:mi> </mml:math> ) symmetry, respectively. The basic V-kagome unit appears in both compounds, but stacking differently. A V 2 Sb 2 layer is sandwiched between two V 3 Sb 5 layers in AV 8 Sb 12 , altering the V-kagome lattice and lowering the symmetry of kagome layer from hexagonal to orthorhombic. In AV 6 Sb 6 , the building block is a more complex slab made up of two half-V 3 Sb 5 layers that are intercalated by Cs cations along the c -axis. Transport property measurements demonstrate that both compounds are nonmagnetic metals, with carrier concentrations at around 10 21 cm −3 . No superconductivity has been observed in CsV 8 Sb 12 above 0.3 K under in situ pressure up to 46 GPa. Compared to CsV 3 Sb 5 , theoretical calculations and angle-resolved photoemission spectroscopy reveal a quasi-two-dimensional electronic structure in CsV 8 Sb 12 with C 2 symmetry and no van Hove singularities near the Fermi level. Our findings will stimulate more research into V-based kagome quantum materials.