Research Projects

There is a growing global demand for faster, energy efficient, and high-density memory devices to meet the needs of data driven technologies. For the last five decades, progress of digital technology has been largely driven by complementary metal oxide semiconductor (CMOS) technology and serves as the backbone of integrated circuits in modern electronic devices. However, as CMOS approaches its scaling limits, challenges like increased standby power dissipation and charge leakage are become critical concerns. Two dimensional (2D) van der Waals (vdW) materials have emerged as promising candidates, particularly when engineered into adjustable heterostructures even in atomically thin limit. They provide clean interfaces and allow precise control over composition and electronic properties, eliminating the need for lattice matching. Hence these can be more suitable for next generation non-volatile memory application at smaller dimension. This proposal focuses fabrication of 2D devices in form of vdW heterostructures by integrating 2D magnetic materials such as CrX₃ (X = I, Cl) and CrSBr, in order to enable electrically controlled spintronic and non-volatile memory functionalities. These vdW magnetic compounds exhibit long-range magnetic order (2D A-type antiferromagnet) down to the monolayer limit, where CrI₃ shows ferromagnetism in monolayer. CrCl₃ and CrSBr both show interlayer antiferromagnetism and intralayer ferromagnetism. Interestingly, they also possess semiconducting property and can be modulated by gating, allowing electrical control over the tunnelling process. We will construct heterostructures integrating the magnetic layer of CrX₃ or CrSBr (as tunnel barrier) with graphene (Gr) electrodes (spin polarized injector) to form spin filter magnetic tunnel junction and electrostatic gate induced switching device. The efficient spin injection in this configuration is very crucial. Due to the peculiar antiferromagnetic alignments of ferromagnetic intralayers, different magnetic states in the magnetic material effectively modifies the spin filter effects and that will be manifested in the tunnel resistance. Also, the proximity-induced exchange interaction can be tuned via electrostatic gating through Gr, potentially enabling low-power switching and paving the way for novel forms of magnetic logic. In this project modulation of spin polarized current, proximity-induced effects, interlayer exchange coupling and non-volatile switching mechanisms will be explored in detail. Unlike traditional MTJs that rely on current-driven mechanisms like spin transfer torque (STT), the use of gate tunable magnetic proximity effects in these 2D systems allows for electric field control of magnetism and tunnelling characteristics, reducing power consumption significantly. This study will contribute significantly to the development of energy-efficient, ultrathin and voltage-controlled memory devices based on 2D magnetic semiconductors.