Enhanced Transport Parameters of Transition Metal Dichalcogenide-Based Double-Barrier Magnetic Tunnel Junction

This paper theoretically examines the impact of integrating 2D transition metal dichalcogenide (TMDCs) materials—MoS₂, MoSe₂, MoTe₂, WS₂, and WSe₂—with a conventional MgO dielectric to fabricate double-barrier penta-layer (DBPL) magnetic tunnel junction (MTJ) structures. The MTJ device proposed herein is distinguished by a DBPL configuration which incorporates the composite tunnel barrier (CTB) of MgO-MX₂-MgO sandwiched between the Fe ferromagnetic electrodes. Using density functional theory (DFT), we conducted a crystallographic analysis on all constituent materials to predict the properties necessary for device operation. Subsequent simulations leveraged an advanced nonequilibrium Green’s function-based (NEGF) quantum transport simulator to quantify critical transport phenomena. Notable metrics such as tunneling magnetoresistance (TMR), differential TMR, and spin-transfer torque (STT), both in-plane and out-of-plane, were determined. Additionally, resistance and differential resistance profiles for parallel and antiparallel alignment states were thoroughly evaluated. Our findings elucidate the essential role of CTB composition in determining MTJ performance attributes, with particular dielectric pairings showing a significant enhancement in TMR ratios and an improved resistance differential without compromising the efficiency of STT. Interestingly, our proposed MTJ device shows a substantial increase in TMR values, ranging from 900% to 4300%, with very high sensitivity ranging from 7.33 × 10⁶ T⁻¹ to 3.36 × 10⁷ T⁻¹.