Record-high mobility and extreme magnetoresistance on kagome-lattice in compensated semimetal Ni 3 In 2 S 2

The kagome-lattice crystal hosts various intriguing properties including the frustrated magnetism, charge order, topological state, superconductivity and correlated phenomena. To achieve high-performance kagome-lattice compounds for electronic and spintronic applications, careful tuning of the band structure would be desired. Here, the electronic structures of kagome-lattice crystal Ni 3 In 2 S 2 were investigated by transport measurements, angle-resolved photoemission spectroscopy as well as ab initio calculations. The transport measurements reveal Ni 3 In 2 S 2 as a compensated semimetal with record-high carrier mobility (∼8683 and 7356 cm 2 V −1 S −1 for holes and electrons) and extreme magnetoresistance (15,518% at 2 K and 13 T) among kagome-lattice materials. These extraordinary properties are well explained by its band structure with indirect gap, small electron/hole pockets and large bandwidth of the 3d electrons of Ni on the kagome lattice. This work demonstrates that the crystal field and doping serve as the key tuning knobs to optimize the transport properties in kagome-lattice crystals. Our work provides material basis and optimization routes for kagome-lattice semimetals towards electronics and spintronics applications.