Control of spin-charge conversion in van der Waals heterostructures

The interconversion between spin and charge degrees of freedom offers incredible potential for spintronic devices, opening routes for spin injection, detection, and manipulation alternative to the use of ferromagnets. The understanding and control of such interconversion mechanisms, which rely on spin-orbit coupling, is therefore an exciting prospect. The emergence of van der Waals materials possessing large spin-orbit coupling (such as transition metal dichalcogenides or topological insulators) and/or recently discovered van der Waals layered ferromagnets further extends the possibility of spin-to-charge interconversion to ultrathin spintronic devices. Additionally, they offer abundant room for progress in discovering and analyzing novel spin-charge interconversion phenomena. Modifying the properties of van der Waals materials through proximity effects is an added degree of tunability also under exploration. This Perspective discusses the recent advances toward spin-to-charge interconversion in van der Waals materials. It highlights scientific developments which include techniques for large-scale growth, device physics, and theoretical aspects. The authors thank H. Okuno for the images in Figs. 2(d)–2(h). All authors acknowledge financial support from the King Abdullah University of Science and Technology under Grant No. ORS-2018-CRG7-3717. The ICN2 authors were also supported by the European Union Horizon 2020 research and innovation program under Grant Agreement Nos. 881603 (Graphene Flagship), 824140 (TOCHA, H2020-FETPROACT-01-2018), and 840588 (GRISOTO, Marie Sklodowska-Curie fellowship). ICN2 is also funded by the CERCA Programme/Generalitat de Catalunya and is supported by the Severo Ochoa program from Spanish MINECO (Grant Nos. SEV-2017-0706, PID2019-111773RB-I00/AEI/10.13039/501100011033, and RYC2019-028368-I/AEI/10.13039/501100011033). The CNRS-CEA authors acknowledge financial support from the European Union Horizon 2020 research and innovation program under Grant Agreement No. 881603 (Graphene Flagship), the French ANR projects MAGICVALLEY (Grant No. ANR-18-CE24-0007), and ELMAX (Grant No. ANR-20-CE24-0015) and from the UGA IDEX IRS/EVASPIN.