Spin Filtering Manipulation in WS₂-based Magnetic Tunnel Junctions

Spintronics has opened a new paradigm through the use of the spin variable as the vector of information and has been largely applied from hard drives read-heads to the STT-MRAMs. While very recent, the introduction of 2D materials in Magnetic Tunnel Junctions (MTJs) has already shown some promising properties[1][2]. The recent advent of the wide TMDC family of 2D semiconductors opened new opportunities for further tailoring of spintronics properties. We will detail a protocol to fabricate spin valves based on CVD grown WS₂ with step by step characterizations in support (Raman, photoluminescence, AFM). The fabrication process is further validated by the measurements of magnetoresistance spin signals above state of the art for 2D semiconductors based MTJs. We then present experimental results on WS₂ spin-filtering tunability with thickness that we discuss in light of its peculiar thickness band-structure evolution, with Density Functional Theory calculations in support. Our work opens the way to the integration of different members of the very large TMDCs family, in order to reveal their spin transport properties in MTJs[3].
[1] Piquemal-Banci et al. J. Phys. D: Appl. Phys. 50, 203002 (2017)
[2] Piquemal-Banci et al. ACS Nano 12, 4712 (2018)
[3] Zatko et al. ACS Nano 12, 14468 (2019)