Research Projects

The discovery of intrinsic long-range ferromagnetism in two-dimensional (2D) layered materials has ignited considerable research interest due to their potential technological applications in low-power spintronic devices [1]. On the other hand, the Mermin-Wagner theorem proposes limitations to have long-range ferromagnetic interactions in the 2D magnets due to thermal fluctuations at finite temperatures. In this regard, the magnetocrystalline anisotropy energy (MAE) becomes crucial to overcome thermal fluctuations and realize long-range 2D ferromagnetism in layered materials [2]. Recent investigations have focused on enhancing the long-range magnetic ordering in several 2D layered magnets such as CrI3, Cr2Ge2Te6, and Cr2Si2Te6. On the other hand, recent theoretical studies suggest that the layered CrxTey systems are potential candidates for realizing the much-anticipated room-temperature 2D ferromagnetism in bulk. Since then, a variety of CrxTey compounds have been grown experimentally and studied for their peculiar 2D ferromagnetism, including CrTe, Cr2Te3, Cr3Te4, Cr4Te5, and Cr5Te8. Generally, CrxTey compounds possess alternating stacks of CrTe2 layers intercalated by the Cr layers (excess) along the crystal growth axis. In addition to their magnetic versatility, these materials have shown skyrmion-like spin textures, enabling emergent topological phases, including the topological Hall effect (THE)—a phenomenon that stems from real-space Berry curvature due to chiral spin arrangements like skyrmion lattices. The THE has been experimentally observed in CrₓTey systems such as Cr₂Te₃ and Cr₅Te₈ and forms the working principle behind topological Hall sensors. These sensors, fabricated from exfoliated CrₓTey flakes in a Hall bar geometry, exhibit distinct hump-like Hall resistivity signals under magnetic fields. Such features provide a robust, non-volatile, and low-power mechanism to detect skyrmions and other spin textures, paving the way for applications in spin logic, high-density memory, neuromorphic hardware, and real-time magnetic imaging. In this proposal, we aim to investigate the family of CrₓTey-based layered systems, focusing on stabilizing the room temperature ferromagnetism and realizing skyrmion-induced topological Hall effect in thin flakes. Through targeted material design and device fabrication, we seek to develop scalable topological Hall sensors and explore tuneable skyrmion superconductivity, both are crucial for next-generation quantum and spintronic technologies As real-life applications of topological superconductors and 2D magnets are very promising as they have the potential to play a vital role in making topological quantum computers and high-density data storage devices, towards which the present materials sciences research community is running. In this regard, adequate research in this direction is inevitable to meet the desired quantum technology. As discussed above, one can notice from the current national and international research status of the proposed scientific problem that 2D magnetism and topological (skyrmionic) superconductivity nationally and internationally have a long way to go. Further, as for the main goal of the proposal, stabilizing the ferromagnetic order in thin-flake CrxTey systems has not been fully explored, nationally or internationally, although some international groups have done a few studies on selected CrxTey compositions. Also, let us emphasize here that “we were the first to discover the skyrmion superconductivity in the Sn intercalated Cr3Te4 single crystal having a superconducting transition temperature of Tc=3.5 K.” Therefore, in this proposal, we would like to explore the other CrxTey systems to increase the skyrmion superconducting transition temperature (Tc) by material engineering of intercalation with alien elements.