Ultrathin Scattering Spin Filter and Magnetic Tunnel Junction Implemented by Ferromagnetic 2D van der Waals Material

Abstract

AbstractEmerging research in 2D materials has promoted the development of nanoelectronics. Ferromagnetic van der Waals (vdW) layered materials can be utilized to implement ultrathin spintronic devices with new functionalities. The theoretical investigation of 2D vdW scattering spin filters and magnetic tunnel junctions consisting of atomically thin Fe3GeTe2 (FGT) are reported. By the nonequilibrium Green's function technique, the spin polarization of ballistic transport through single‐/double‐layer FGT sandwiched between two Cu electrodes is predicted to be 53/85%. In ultrathin FGT‐hBN‐FGT heterostructures, remarkable magnetoresistance is observed, in which maximum (minimum) resistance occurs when the magnetization of two FGT layers is parallel (antiparallel) to each other. For heterostructures consisting of single‐/double‐layer FGT, the magnetoresistance reaches 183/252% at zero‐bias limit. The parallel state of a FGT magnetic tunnel junction exhibits spin polarization larger than 75%. These results suggest the application of magnetic vdW layered materials in ultrathin spintronics.