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:R3 m)symmetry,respectively.The basic Vka...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:R3 m)symmetry,respectively.The basic Vkagome unit appears in both compounds,but stacking differently.AV_(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.展开更多
基金Supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0304700 and 2018YFE0202601)the National Natural Science Foundation of China(Grant Nos.51922105,51772322,52025025,and 52072400)the Beijing Natural Science Foundation(Grant No.Z200005)。
文摘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:R3 m)symmetry,respectively.The basic Vkagome unit appears in both compounds,but stacking differently.AV_(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.
