Electrical Detection in Two‐Terminal Perpendicularly Magnetized Devices via Geometric Anomalous Nernst Effect

ABSTRACT The non‐uniform current distribution arising from either the current crowding effect or the hot spot effect provides a method to tailor the interaction between thermal gradient and electron transport in magnetically ordered systems. Here, we apply the device structural engineering to realize an in‐plane inhomogeneous‌ temperature distribution within the conduction channel, and the resulting geometric anomalous Nernst effect (GANE) gives rise to a nonlinear effect whose polarity corresponds to the out‐of‐plane magnetization of Co/Pt multi‐layer thin film, and its resistance is linearly proportional to the applied current. By optimizing the aspect ratio of a convex‐shaped device, the effective temperature gradient can reach up to 0.3 K µm −1 along the y‐ direction, leading to a GANE signal of 28.3 µV. Moreover, we demonstrate electrical write and read operations in the perpendicularly magnetized Co/Pt‐based spin–orbit torque device with a simple two‐terminal structure. Our results unveil a new pathway to utilize thermoelectric effects for constructing high‐density magnetic memories.