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

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.

SUBMITTER: Shi M 

PROVIDER: S-EPMC9120444 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature