Giant enhancement of spin transport in transition metal dichalcogenides/ferromagnet heterostructures via 3d metal intercalation-driven interface orbital hybridization

Interfacial spin transport plays a critical role in spintronic devices, which rely on functional thin layers of magnetic/non-magnetic materials and their interfaces. Two-dimensional materials like transition metal dichalcogenides (TMDCs) present unique opportunities but suffer from large interfacial barriers that suppress spin generation and manipulation. Despite this challenge, systematic investigations and effective control methods for interfacial spin transport in TMDC/ferromagnet heterostructures remain scarce. Here, we demonstrate that interfacial engineering via 3d metal intercalation drastically enhances spin transport in MoS₂/CoFeB heterostructures. By introducing ultrathin interfacial layers (Al, Ti, Cu) between MoS₂ and CoFeB, we achieve significant modulation of spin-mixing conductance (increase of 3300 %). First-principles calculations reveal that this enhancement arises from a downshift of unoccupied Mo d-orbitals induced by interfacial orbital hybridization, allowing the formation of low-resistance ohmic contacts. These findings establish interface intercalation as a potent strategy for optimizing spin transport in TMDC-based spintronic heterostructures, offering critical insights for device design and performance enhancement.