Exchange Coupling-Induced\nGiant Spin Splitting in\nTwo-Dimensional M<sub>2</sub>X<sub>3</sub>/TMD Heterostructures

Two-dimensional (2D) magnet–insulator heterostructures\nhave\nshown potential as promising platforms for tuning valleytronics and\nspintronics. Thanks to their two-dimensional nature, possible candidates\nfor realizing even richer quantum phases have been extended to a huge\nfamily of materials. Targeting the search for heterostructures with\nbetter performance, we suggest a Dirac electronic system M<sub>2</sub>X<sub>3</sub> (M = transition metal, X = O/S) coupled with transition\nmetal dichalcogenides (TMDs) as a new heterostructure family. We conduct\na systematic first-principles study on electronic band properties\nand magnetic properties of M<sub>2</sub>X<sub>3</sub>/TMD heterostructures.\nOn this ground, we reveal that there exists a giant spin splitting\nlarger than the previously reported Cr-based system and identify the\norigin of this giant spin splitting as exchange coupling in this heterostructure.\nThe efficient Zeeman field is up to 580 T in Cr<sub>2</sub>O<sub>3</sub>/WS<sub>2</sub>. Our study suggests that M<sub>2</sub>X<sub>3</sub>/TMD can be a potential platform for realizing skyrmions. Due to\nits advantage as a simpler structure and a Dirac electronic system\nover the reported CrI<sub>3</sub> family in realization of such a\nspin system, M<sub>2</sub>X<sub>3</sub>/TMD holds the promise of discovering\neven richer quantum phases within the system.