Periodic Reporting for period 1 - CHEERS (Chirality controlled spin to charge interconversion in Tellurium)
Reporting period: 2024-01-01 to 2025-12-31
CHEERS (Chirality controlled spin to charge interconversion in Tellurium) investigated how low-symmetry van der Waals and telluride materials can generate and convert spin information for future low-power spintronic devices. The project focused on understanding spin-charge interconversion (SCI) in chiral tellurium and related materials using a combined experimental toolbox including magnetotransport, magneto-optical Kerr effect (MOKE), and ferromagnetic resonance/spin pumping (FMR/SP).
During the fellowship, the project achieved major progress in experimental capability building and in alternative low-symmetry materials, while facing significant fabrication bottlenecks for the originally planned Te-based device platforms. Extensive fabrication campaigns on Te/YIG and Te-based heterostructures identified critical adhesion and yield limitations. In response, the work plan was adapted through scientifically justified pivots: (i) successful MOKE measurements during secondment at ETH Zurich on conductive low-symmetry vdW materials, where an unconventional current-induced spin accumulation was detected; (ii) implementation of a PPMS-compatible RF/FMR measurement platform (2 K, 9 T) at the host institution, including iterative probe development with collaborators; (iii) productive exploitation of layered magnetic and telluride systems beyond the original Te/CGT route, including published results on ferromagnetism above 200 K in intercalated CrSBr and follow-up FMR dynamics measurements, and non-reciprocal transport in low symmetry Te-based vdW conductors (manuscript in preparation).
The project delivered results beyond the state of the art in several ways: (1) it established a new PPMS-FMR/SP-ready capability in the host group for layered magnetic materials and thin-film bilayers; (2) it generated transferable know-how on microfabrication constraints and mitigation strategies for Te and related low-symmetry vdW devices; (3) it demonstrated MOKE-based detection workflows on alternative low-symmetry vdW materials, providing a practical route to study unconventional spin accumulation when the original Te platform was not technically viable; and (4) it contributed to new materials advances relevant to spintronics and orbitronics, including flexible Bi2Te3 thin films and intercalated CrSBr with tuneable ferromagnetism above 200 K. These outcomes strengthen experimental infrastructure, methods and materials knowledge for future spintronic device development in Europe.