Extraordinary anisotropic magnetoresistance in CaMnO3/CaIrO3 heterostructures

The realization of fourfold anisotropic magnetoresistance (AMR) in 3d-5d heterostructures has boosted major efforts in antiferromagnetic (AFM) spintronics. However, despite the potential of incorporating strong spinorbit coupling, only small AMR signals have been detected thus far, prompting a search for mechanisms to enhance the signal. In this paper, we demonstrate an extraordinarily elevated fourfold AMR of 70% realized in CaMnO3/CaIrO3 thin film superlattices. We find that the biaxial magnetic anisotropy and the spin-flop transition in a nearly Mott insulating phase form a potent combination, each contributing one order of magnitude to the total signal. Dynamics between these phenomena capture a subtle interaction of pseudospin coupling with the lattice and external magnetic field, an emergent phenomenon creating opportunities to harness its potential in AFM spintronics.

Automated summary

This paper demonstrates an extraordinarily elevated fourfold anisotropic magnetoresistance (AMR) in 3d-5d heterostructures and uncovers the contributions of biaxial magnetic anisotropy and spin-flop transition to the signal. The subtle interaction of pseudospin coupling with the lattice and external magnetic field captured in this emerging phenomenon holds great potential in AFM spintronics.