Large Tunneling Electroresistance, Tunneling Magnetoresistance, and Regulatable Negative Differential Conductance in a van der Waals Antiferroelectric Multiferroic Tunnel Junction

Multifunctional tunnel junction is a kind of electronic device and the emergence of van der Waals (vdW) materials provides a promising opportunity for the development of multifunctional tunnel junctions and the miniaturization of electronic devices beyond Moore's law. Here, we propose a symmetric vdW antiferroelectric multiferroic tunnel junction (AFMFTJ) based on ${\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$/$h$-BN/bilayer-${\mathrm{In}}_{2}{\mathrm{Se}}_{3}$/$h$-$\mathrm{BN}/{\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$ vdW heterostructure, and investigate the spin-dependent transport of this vdW AFMFTJ by using nonequilibrium Green's function combined with density-functional theory. It is found that multiple resistance states are realized in this proposed vdW AFMFTJ and the considerable tunneling electroresistance ratio of about $1.0\ifmmode\times\else\texttimes\fi{}{10}^{4}\mathrm{%}$ and the large tunneling magnetoresistance ratio of up to 695% are simultaneously achieved at zero bias. Interestingly, the regulatable negative differential conductance (NDC) by magnetic field and electric field is produced in this vdW AFMFTJ under bias voltages. The NDC effect originates from the changes in the conductive channels of ${\mathrm{Fe}}_{3}{\mathrm{Ge}\mathrm{Te}}_{2}$ electrodes and the electronic states of the ${\mathrm{In}}_{2}{\mathrm{Se}}_{3}$ barrier under different bias voltages. This work not only benefits exploring of the tunnel junction with NDC effect, but also provides a promising route for the design of multifunctional microelectronic devices based on vdW materials.