Proposal for a high-speed 2D-Xene-based antiferromagnetic memory cell*

We propose a read-write switch using antiferromagnets coupled with a spin-valley locked channel [1] in a 2D Xene material. We couple the Keldysh non-equilibrium Green’s function (NEGF) [2] formalism with the anti-ferromagnetic Landau-Lifshitz-Gilbert (LLG) equation to uncover novel capabilities of our device structure to store and manipulate spin information.

The simulations are based on the coupled NEGF-LLG framework using an implicit Gauss-Seidel Project scheme. We utilize the high magnetoresistance offered in the topological quantum spin valley Hall phase [1,3] to develop a reading mechanism to store bits as orthogonal configurations of the free antiferromagnetic lead. The proposed device induces a non-equilibrium spin density staggered across the sublattices to generate a spin-transfer torque to switch from the low-resistance state to the high-resistance state efficiently. We also demonstrate pico-second order switching in the memory cell with low critical current and energy cost.

[1] K. Jana and B. Muralidharan, npj 2D Mat. and Appl., 6, 19, (2022). 

[2] Datta, S. (2005). Quantum Transport: Atom to Transistor. Cambridge: Cambridge University Press.

[3] Yafang Xu, G. J. Phys. Rev. B 95, 155425, (2017).