Band Structure Engineering of van der Waals Heterostructures for Spintronics

The discovery of graphene has opened novel exciting opportunities in terms of functionalities and performances for spintronics devices.[1] This started a wide exploration of a large variety of 2D crystals for spintronics with the hope to exploit some of their unique topological properties. We will present here experimental results concerning integration of 2D materials in vertical Magnetic Tunnel Junctions (MTJ).[2] The direct growth of the 2D layers preserves the spin polarization properties of ferromagnetic spin sources, enabling the use of these van der Waals materials for spintronics devices. We will discuss the measured experimental spin signals in light of bulk band structure spin filtering effect as usually observed with MgO, but also highlight the role of interfacial hybridization (a.k.a. spinterface) for spin selection with ab-initio calculations in support. We will further introduce a novel pulsed laser deposition (PLD) approach for the definition of complex van der Waals heterostructures of 2D materials in magnetic tunnel junctions.[3] Overall, the presented experiments unveil promising approaches for the quantum engineering of multifunctional 2D materials heterostructures for spintronics.<br/><br/>[1] Dlubak Nat Phys 8, 557 (2012); Seneor MRS Bull 37, 1245 (2012); Dlubak ACS Nano 6, 10930 (2012); Martin APL 107, 012408 (2015); Martin Adv. Quantum Technol. 5, 2100166 (2022)<br/><br/>[2] Piquemal-Banci Nat Comm 11, 5670 (2020); Zatko ACS Nano 16, 14007 (2022); Piquemal-Banci ACS Nano 12, 4712 (2018); Galbiati PRApplied 12, 044022 (2019); Zatko et al. ACS Nano 13, 14468 (2019) ; Yang Nature 606, 663 (2022); Zatko Nano Letters 23, 34 (2023)<br/><br/>[3] Godel ACS Appl Nano Mater 3, 7908 (2020); Zatko ACS Nano 15, 7279 (2021); Wei et al. Adv Materials Interf (2024)