The de Haas–van Alphen quantum oscillations in the kagome metal RbTi₃Bi₅

Abstract

The kagome system usually attracts great interest in condensed matter physics due to its unique structure hosting various exotic states such as superconductivity (SC), charge density wave (CDW), and nontrivial topological states. Topological semimetal RbTi3Bi5 consisting of the Ti kagome layer shares a similar crystal structure to topological correlated materials AV3Sb5 (A = K, Rb, Cs) but without the absence of CDW and SC. Systematic de Haas-van Alphen (dHvA) oscillation measurements are performed on the single crystals of RbTi3Bi5 to pursue nontrivial topological physics and exotic states. Combining with theoretical calculations, detailed Fermi surface topology and band structure are investigated. A two-dimensional (2D) Fermi pocket β is revealed with a light-effective mass consistent with the semimetal predictions. Landau Fan of RbTi3Bi5 reveals a zero Berry phase for the β oscillation in contrast to that of CsTi3Bi5. These results suggest the kagome RbTi3Bi5 is a good candidate to explore nontrivial topological exotic states and topological correlated physics.