Harmonic measurements of the longitudinal and transverse voltages in Bi-Sb/Co bilayers are presented. A large second harmonic voltage signal due to the ordinary Nernst effect is observed. In experiments where a magnetic field is rotated in the film plane, the ordinary Nernst effect shows the same angular dependence in the transverse voltage as the damping-like spin-orbit torque and in the longitudinal voltage as the unidirectional spin-Hall magneto-resistance respectively. Therefore, the ordinary Nernst effect can be a spurious signal in spin-orbit torque measurements, leading to an overestimation of the spin-Hall angle in topological insulators or semimetals.
@article{arxiv.1810.05674,
title = {Spin-Orbit Torque and Nernst Effect in Bi-Sb/Co Heterostructures},
author = {Niklas Roschewsky and Emily S. Walker and Praveen Gowtham and Sarah Muschinske and Frances Hellman and Seth R. Bank and Sayeef Salahuddin},
journal= {arXiv preprint arXiv:1810.05674},
year = {2019}
}