Non-reciprocal magnetoresistance, directional inhomogeneity and mixed symmetry Hall devices

Abstract

Phenomenology similar to the nonreciprocal charge transport violating Onsagers reciprocity relations can develop in directionally inhomogeneous conducting films with nonuniform Hall coefficient along the current trajectory. The effect is demonstrated in ferromagnetic CoPd films and analyzed in comparison with the unidirectional magnetoresistance phenomena. We suggest to use an engineered inhomogeneity for spintronics applications and present the concept of mixed symmetry Hall devices in which transverse to current Hall signal is measured in a longitudinal contacts arrangement. Magnetization reversal and memory detection is demonstrated in the three terminal and the partitioned normal metal-ferromagnet (NM - FM) device designs. Multi-bit memory is realized in the partitioned FM-NM-FM structure. The relative amplitude of the antisymmetric signal in the engineered ferromagnetic devices is few percent which is 10 to 1000 times higher than in their unidirectional magnetoresistance analogues.

References in corpus (5)

• Engineering symmetry breaking in two-dimensional layered materials
• Large Unidirectional Magnetoresistance in a Magnetic Topological Insulator
• Electrical detection of magnetization reversal without auxiliary magnets
• A two-terminal spin valve device controlled by spin-orbit torques with enhanced giant magnetoresistance
• Impact of invasive metal probes on Hall measurements in semiconductor nanostructures