Reconfigurable spin tunneling diode and giant tunneling magnetoresistance in a symmetric van der Waals double-barrier magnetic tunnel junction

The tunneling diodes are commonly used to control the direction of current in semiconductor devices and are an essential circuit element in modern electronics. Here, we propose a multifunctional and reconfigurable spin-dependent tunneling diode (spin TD) based on a symmetric van der Waals (vdW) double-barrier magnetic tunnel junction (DBMTJ), where if the magnetic moments of two ferromagnetic electrodes are antiparallel, a significant spin TD effect is produced in the symmetric vdW DBMTJ due to the spin splitting of the middle ferromagnetic metal layer. Using first-principles calculations, we find that the proposed spin TD effect and three significantly different resistance states with giant tunneling magnetoresistance are achieved in the vdW DBMTJs based on the ${\mathrm{Fe}}_{3}{\mathrm{GaTe}}_{2}$/${\mathrm{GeI}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{GaTe}}_{2}/{\mathrm{GeI}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{GaTe}}_{2}$ and ${\mathrm{Fe}}_{3}{\mathrm{GaTe}}_{2}/{\mathrm{GeI}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{GeTe}}_{2}/{\mathrm{GeI}}_{2}/{\mathrm{Fe}}_{3}{\mathrm{GaTe}}_{2}$ vdW heterostructures. Moreover, the spin TD effect can be modulated by changing the magnetic configuration of the symmetric vdW DBMTJ through the magnetic field. Our work holds valuable implications for developing multifunctional and reconfigurable nondoped diode devices.