Spin-orbitronic devices can integrate memory and logic by exploiting spin-charge interconversion (SCI), which is optimized by design and materials selection. In these devices, such as the magnetoelectric spin-orbit (MESO) logic, interfaces are crucial elements as they can prohibit or promote spin flow in a device as well as possess spin-orbit coupling resulting in interfacial SCI. Here, we study the origin of SCI in a Py/Cu/W lateral spin valve and quantify its efficiency. An exhaustive characterization of the interface between Cu and W electrodes uncovers the presence of an oxidized layer (WOx). We determine that the SCI occurs at the Cu/WOx interface with a temperature-independent interfacial spin-loss conductance of G∣∣≈ 20 × 1013Ω−1m−2 and an interfacial spin-charge conductivity σSC=−1610 Ω−1cm−1 at 10 K (−830 Ω−1cm−1 at 300 K). This corresponds to an efficiency given by the inverse Edelstein length λIEE=−0.76 nm at 10 K (−0.4 nm at 300 K), which is remarkably larger than in metal/metal and metal/oxide interfaces and bulk heavy metals. The large SCI efficiency at such an oxidized interface is a promising candidate for the magnetic readout in MESO logic devices.
@article{arxiv.2211.09250,
title = {Emergence of large spin-charge interconversion at an oxidized Cu/W interface},
author = {Inge Groen and Van Tuong Pham and Stefan Ilić and Won Young Choi and Andrey Chuvilin and Edurne Sagasta and Diogo C. Vaz and Isabel C. Arango and Nerea Ontoso and F. Sebastian Bergeret and Luis E. Hueso and Ilya V. Tokatly and Fèlix Casanova},
journal= {arXiv preprint arXiv:2211.09250},
year = {2023}
}