Superconductivity and Normal-State Properties of Kagome Metal RbV_3Sb_5 Single Crystals

We report the discovery of superconductivity and detailed normal-state physical properties of RbV_3Sb_5 single crystals with V kagome lattice. RbV_3Sb_5 single crystals show a superconducting transition at T_\rm c\sim 0.92 K. Meanwhile, resistivity, magnetization and heat capacity measurements indicate that it exhibits anomalies of properties at T^*\sim 102–103 K, possibly related to the formation of charge ordering state. When T is lower than T^*, the Hall coefficient R_\rm H undergoes a drastic change and sign reversal from negative to positive, which can be partially explained by the enhanced mobility of hole-type carriers. In addition, the results of quantum oscillations show that there are some very small Fermi surfaces with low effective mass, consistent with the existence of multiple highly dispersive Dirac band near the Fermi energy level.