Fig. 1

Sample geometry and in-plane temperature distribution. a The MTJ layer stack with the corresponding thicknesses. The magnetization \(M\), with respect to the in-plane temperature gradient \(\nabla T\) (black arrows) their relation is given by the in-plane varied angle \(\phi\). b MTJ between the Au top and the Ta bottom contacts. The direction of the incoming laser beam, the external magnetic field \(\mu _0H\) and the thermovoltage measurement configuration are indicated within the coordinate axes. c–e False color plots showing the in-plane temperature gradients in the top CoFeB electrode for three heating laser spot positions at the junction edges obtained from COMSOL simulations. The MTJ areas are indicated by the dashed lines. Heating at the end of the long (short) axis results in the main temperature gradient in y-direction (x-direction) as shown in c (e) and indicated by the black arrows. Graph d shows the scenario, when the heating laser spot is placed on the edge between both major ellipses axes, resulting in the main temperature gradient at an angle between the main temperature gradient at an angle between the two