doi:10.1088/1361-6463/ae5ddeengMorales-Aragonés, José IgnacioGroen, IngeHueso, Luis ECasanova, FèlixPardo, José ÁngelSánchez-Azqueta, CarlosDe Teresa, José MaríaSangiao, SorayaUltrathin tungsten films enabling enhanced electrical response to spin currentsART-2026-149147The efficient detection of spin currents is crucial for the development of next-generation spintronic devices. Here, we demonstrate that ultrathin W layers, with thicknesses down to 2 nm—equivalent to only four atomic planes—allow for highly efficient spin-to-charge conversion. From spin pumping experiments in YIG/W bilayers, we analyzed the inverse spin Hall effect (SHE) voltage dependence on W thickness and extracted a spin Hall conductivity of σSH = −1.14(6) × 105 Ω −1 m−1, yielding effective spin Hall angles ranging from −0.27(4) to −0.88(4) over the investigated thickness range. Furthermore, assuming the Elliott–Yafet spin scattering mechanism dominates, we estimate a spin diffusion length λsd = 4.3(5) × 10−15Ωm2/ρW, where the W resistivity ρW is strongly dependent on thickness. Structural characterization, together with roomtemperature electrical resistivity measurements and the high spin-to-charge conversion efficiency observed, confirms the stabilization of the β-phase in these ultrathin W layers. We demonstrate that the monotonic increase of the inverse SHE voltage with decreasing W thickness persists down to 2-nm-thick W layer, reflecting the extremely short spin diffusion length. This allows for efficient spin-current detection in W layers below 5 nm, effectively doubling the voltage output at half the thickness. In the thinnest sample, a continuous 2-nm-thick W layer, the generated voltage exceeds 0.5 mV—well within the operating range of conventional electronics. These findings demonstrate not only the feasibility of spin-current detection in ultrathin W, but also its compatibility with conventional electronics. They highlight the strong potential of integrating ultrathin W layers with high-quality YIG films for the development of energy-efficient spintronic devices and sensors.2026http://zaguan.unizar.es/record/17106310.1088/1361-6463/ae5ddehttp://zaguan.unizar.es/record/171063oai:zaguan.unizar.es:171063info:eu-repo/grantAgreement/ES/AEI/PID2023-146451OB-I00info:eu-repo/grantAgreement/ES/AEI/PID2023-150244OB-I00info:eu-repo/grantAgreement/ES/DGA/E13-23Rinfo:eu-repo/grantAgreement/ES/DGA/E29-24info:eu-repo/grantAgreement/ES/DGA/T33-24info:eu-repo/grantAgreement/ES/MCIU/PID2020-112914RB-I00info:eu-repo/grantAgreement/ES/MICIU/PID2021-122511OB-I00info:eu-repo/grantAgreement/ES/MICIU/PID2024-155708OB-I00Journal of physics. D, Applied physics 59, 17 (2026), 175301 [13 pp.]byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess