Fully Electronically Controlled High-Efficiency Multiferroic Tunnel Junctions Composed of Bilayer CuCrSe₂ with Anti-ferromagnetic and Anti-ferroelectric Properties

Multiferroic tunnel junctions (MFTJs), typically consisting of ferromagnetic (FM) electrodes and a ferroelectric (FE) barrier, have demonstrated broad spintronic applications due to their multiple nonvolatile states. However, they face challenges related to stray fields and FM/FE interfacial issues. Here, a fully electronically controlled read–write spintronic device component MFTJ is designed by simulation using the two-dimensional multiferroic CuCrSe2 synthesized by experiments. Instead of using separate FM and FE materials as in conventional MFTJs, we introduce van der Waals (vdW) MFTJs based solely on bilayer CuCrSe2, possessing both A-type antiferromagnetic (AFM) and antiferroelectric (AFE) properties of the ground state. After adjusting bilayer CuCrSe2, the electric polarization from anti-ferroelectric to ferroelectric, the magnetization state changes from anti-ferromagnetic to ferromagnetic, which can provide both spin polarization and ferroelectric polarization sources within the device. Combining non-equilibrium Green’s function with density functional theory, we systematically investigate the transport properties of CuCrSe2-based vdW MFTJs and find superior device performance. This includes a giant tunneling magnetoresistance (TMR) of 2873.38%, a tunneling electroresistance (TER) of up to 3410.71%, and an ultralow resistance-area (RA) product of 0.45 Ω·μm2. Due to its small lattice mismatch and large spin–orbit torque of PtTe2, this material is proposed as an ideal candidate for integration into CuCrSe2-based vdW MFTJs, enabling fully electronical control of spintronic devices. These findings suggest that two-dimensional multiferroic CuCrSe2 holds great promise for the development of high-performance logic and memory devices.