Nonreciprocal Transport in a Rashba Ferromagnet, Delafossite PdCoO<sub>2</sub>
Jin Hong Lee, T. Harada, Felix Trier, Lourdes Marcano, Florian Godel, S. València, Atsushi Tsukazaki, Manuel Bibès
Abstract
Rashba interfaces yield efficient spin-charge interconversion and give rise to nonreciprocal transport phenomena. Here, we report magnetotransport experiments in few-nanometer-thick films of PdCoO2, a delafossite oxide known to display a large Rashba splitting and surface ferromagnetism. By analyzing the angle dependence of the first- and second-harmonic longitudinal and transverse resistivities, we identify a Rashba-driven unidirectional magnetoresistance that competes with the anomalous Nernst effect below the Curie point. We estimate a Rashba coefficient of 0.75 ± 0.3 eV Å and argue that our results qualify delafossites as a new family of oxides for nanospintronics and spin–orbitronics, beyond perovskite materials.