Cluster-assembled superatomic crystals for chirality-dependent charge-to-spin conversion

Abstract

In chiral materials, spins and chirality are coupled via spin-orbit interaction, provoking a fast-growing field of chiral spintronics. Compared with the widely explored chiral molecules, exploration of chirality-dependent spin effects in crystals and supramolecules remain limited. Here we assemble chiral superatomic crystals MXTe4 (M = transition metal; X = Ga or Ge) using telluride tetrahedra clusters as building blocks. Distinct from atomic crystals, these assembled monolayers have tunable symmetries and electronic characteristics by tilting the tetrahedral units through the variation of inter-cluster interaction. Dresselhaus-type spin textures and anisotropic spin Hall effect with inversed sign of spin current under opposite geometrical handedness are demonstrated in these chiral monolayers by symmetry analysis and verified by ab initio calculations. These results provide an innovative paradigm for assembling superatomic crystals with designated symmetry and hierarchical structures to access the chirality-driven quantum effects.