Bimodal Spin Switch Emerging from Hybridized 2D MoS₂/Ferromagnet Interfaces.

Abstract

Over the past decade, MRAMs developments have focused on improving magnetic tunnel junctions while using magnetic electrodes with fixed properties as spin sources. Interestingly, 2D semiconductors offer interface tailoring opportunities for spin valve devices, with many atomically thin materials now available. However, integrating them with oxidation-prone spintronics materials remains a challenge. Here, spin devices are fabricated and evaluated with large-scale MoS₂ directly grown on a monocrystalline ferromagnetic spin source. While most spin transport experiments with 2D semiconductors focus on their isolated dielectric properties, the presented approach unlocks an additional spin manipulation opportunity from MoS₂ hybridization with ferromagnetic electrodes. The experimental results show a substantial tunnel magnetoresistance (TMR) value of over 65%, an order of magnitude higher than previously observed for exfoliated 2D semiconductor-based devices. A non-monotonic dependence of the spin signal on the applied bias, including a sign reversal, is also uncovered, which is attributed to the modulation of the MoS₂ band structure by the ferromagnetic electrode. Ab initio calculations support these findings by illustrating how the MoS₂ band structure evolves upon hybridization, introducing a pronounced exchange-induced spin splitting and resulting in an unusual bimodal spin response. This study demonstrates the unique spin manipulation opportunities offered by 2D semiconductors unlocked by direct integration.