Abstract
Using element-specific measurements of the ultrafast demagnetization of Ru/Fe65Co35 hetero-structures, we show that Ru can exhibit a significant magnetic contrast (3% asymmetry) resulting from ultrafast spin currents emanating from the demagnetization process of the FeCo layer. We use this magnetic contrast to investigate how superdiffusive spin currents are affected by the doping of heavy elements in the FeCo layer. We find that the spin currents are strongly suppressed, and that the recovery process in Ru slows down by Re doping. This is in accordance with a change in interface reflectivity of spin currents as found by the superdiffusive spin transport model.
| Original language | English |
|---|---|
| Article number | 064427 |
| Journal | Physical Review B |
| Volume | 108 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 24 Aug 2023 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work was supported by the Swedish Research Council (VR, Contracts No. 2017-03799, No. 2021-04658, and No. 2021-5395), the Olle Engkvists Stiftelse (Grant No. 182-0365), Carl Tryggers Stiftelse (Grant No. 17:241), and by the Swedish National Infrastructure for Computing (SNIC), through Grant Agreement No. 2018-05973. This work was furthermore funded by the European Union's Horizon2020 Research and Innovation Programme under FET-OPEN Grant Agreement No. 863155 (s-Nebula). P.M.O. acknowledges support by the Deutsche Forschungsgemeinschaft, project ID 328545488, through CRC/TRR 227 “Ultrafast Spin Dynamics”, project MF. R.G. acknowledges DESY (Hamburg, Germany) for the provision of experimental facilities. Parts of this research were carried out at beamline P09 at PETRA III under proposal No. I-20200894 EC. We are grateful to M. S. D. Graulich and Dr. T. Kuschel (Bielefeld University) for developing within the long-term Project No. LTP I-20170016 the vacuum chamber for the vector electromagnet used in this work and Prof. G. Reiss (Bielefeld University) for contributing within LTP II-20190009 to the in-vacuum silicon drift detector used in this work. S.S. gratefully acknowledges the financial support of SERB with a File No. SRG/2022/000191 and the Axis Grant at Ashoka University, India for the funding.