Magnetoresistance of Ni/WSe 2 /Ni junctions: robustness against the thickness of WSe 2 .

Magnetoresistive materials are vital for the development of storage devices. Using the first-principles transport simulations with nonequilibrium Green's function calculation, we investigate the magnetoresistive properties of Ni/WSe 2 /Ni junctions with m -layers of WSe 2 ( m = 1, 2, ⋯ ,6). For m ≤ 2, the junctions are metallic inspite of the semiconducting nature of few-layer WSe 2 . However, the junctions exhibit transport gaps for m > 2. Interestingly, magnetoresistance of the junctions stays around 6% when there are more than one layer of WSe 2 in the center, which is closely related to the robust spacial variation of interfacial properties and can be attributed to no spin flipping in tunneling regions. Our results suggest that Ni/WSe 2 /Ni junctions have a robust magnetoresistance which is insensitive to the thickness of WSe 2 .