Anisotropic Hanle line shape via magnetothermoelectric phenomena
journal contributionposted on 26.11.2018, 14:55 by K.S. Das, Fasil Dejene, B.J. van Wees, I.J. Vera-Marun
We observe anisotropic Hanle line shape with unequal in-plane and out-of-plane nonlocal signals for spin precession measurements carried out on lateral metallic spin valves with transparent interfaces. The conventional interpretation for this anisotropy corresponds to unequal spin relaxation times for in-plane and out-of-plane spin orientations as for the case of two-dimensional materials like graphene, but it is unexpected in a polycrystalline metallic channel. Systematic measurements as a function of temperature and channel length, combined with both analytical and numerical thermoelectric transport models, demonstrate that the anisotropy in the Hanle line shape is magnetothermal in origin, caused by the anisotropic modulation of the Peltier and Seebeck coefficients of the ferromagnetic electrodes. Our results call for the consideration of such magnetothermoelectric effects in the study of anisotropic spin relaxation.
We acknowledge the financial support of the Zernike Institute for Advanced Materials and the Future and Emerging Technologies (FET) programme under FET-Open Grant No. 618083 (CNTQC).