Origin and enhancement of magnetoresistance in antiferromagnetic tunnel junctions: spin channel selection rules

Antiferromagnetic materials offer superior stability and ultra-fast spin reversal, making them ideal for next-generation magnetoresistive memory. However, magnetoresistance in antiferromagnetic tunnel junctions (AFMTJs) is small because the two spin channels are typically identical. Here, we demonstrate that non-zero or even huge tunneling magnetoresistance (TMR) can be achieved in AFMTJs through a spin-channel selection model, specifically by manipulating the interface tilt angle (ITA) to control the different tunneling distances of the two spin channels. Using 2D antiferromagnetic FeTe-based AFMTJs as an example, we find that varying ITAs can result in giant TMR up to 10⁹%, verifying the spin-channel selection rule in AFMTJs. These findings pave a novel avenue for efficient data manipulation in antiferromagnetic materials through structural engineering.