Asymmetric nonlocal signal induced by thermoelectric effects in a lateral spin valve

Abstract

Abstract We demonstrate that the heat flow arising from the Joule heating produces not only the conventional thermal spin injection but also additional thermo-electric effects both in current and voltage probes. The excellent thermal spin injection property for the CoFeAl enables us to distinguish the ordinal thermal spin valve signal and the unconventional asymmetric field dependence in the nonlocal 2nd harmonic signal. We show that the observed unique field dependence can be well explained by the anomalous Nenrst effect in the ferromagnetic voltage probe and the anomalous thermal Hall effect in the ferromagnetic current probe. The validity of the proposed mechanism was confirmed in various devices with different probe configurations.