A Review on Novel Low‐Dimensional Materials based Magnetic Tunnel Junctions: Opportunities, Challenges, and Applications

Abstract Spintronics‐based magnetic random‐access memory (MRAM) represents a transformative leap in memory technology by harnessing both the spin and charge of an electrons for non‐volatile, high‐density, and ultrafast data storage. At the heart of MRAM lies the magnetic tunnel junction (MTJ), due to its cost‐effectiveness and scalability. Achieving high tunnel magnetoresistance (TMR) necessitates advanced fabrication techniques, precise material growth, and optimized device design. The advent of low‐dimensional materials (LDMs) such as 2D semiconductors (TMDs, graphene), insulators ( h ‐BN, MgO, BNNT), and magnetic materials (CrI 3 , Fe 3 GeTe 2 , MX 3 ) has revolutionized MTJ design. These LDMs eliminate interfacial bonding, surface and internal defects issues that are inherently found in bulk counterparts enabling defect‐free structures, enhanced TMR ratio and room‐temperature operation. h ‐BN as tunnel material and selection of electrode and barrier from the same family (e.g., SrRuO 3 /SrTiO 3 ) mitigates lattice, conduction, and spin mismatch, while van der Waals (vdWs) heterostructures enhance spin injection efficiency. However, understanding the impact of doping, defects, and strain engineering on LDM‐MTJs performance requires deeper exploration. Despite significant advancements in MTJ technology, critical challenges persist in achieving high interfacial quality, scalable fabrication processes, and material stability under operational stress. This factor remains critical barriers for their widespread adoption, necessitating innovative solutions in future research.