Research Projects

This ANRF-NPDF proposal aims to investigate and control the interaction between the excitonic states and magnetic ordering in emerging semiconducting two-dimensional (2D) magnetic materials (2DMMs) and their heterostructure with transition metal dichalcogenides (TMDCs) such as MoS₂, WS₂, and WSe₂. The finding of intrinsic magnetism in van der Waals layered magnetic materials such as CrSBr, NiPS₃, FePS₃ has unlocked unprecedented prospects to explore spintronic and valleytronic physics. However, key questions regarding how the excitons interact with magnetic order in magnetic 2D systems and how the magnetic exchange interaction or magnetic proximity effects can be engineered at the interface of TMDC/2DMM heterostructures remain largely unanswered. So, this project proposal is well structured into two modules to counter these challenges. Module 1 emphasizes unexplored scientific queries and is divided into three work packages and corresponding deliverables. In WP1, we are addressing to investigation of exciton coupling to magnetic ordering and linear dichroism in 2DMMs particularly in antiferromagnets such as CrSBr, NiPS₃, FePS₃ using temperature and polarization dependent absorption, reflection, PL, and Raman spectroscopy. These studies will demonstrate exciton anisotropy and potential symmetry breaking, which is linked to magnetic phases. In WP2, we will explore magnetic proximity effects and exchange interactions at TMDC/2DMM interfaces using magneto-optical Kerr effect (MOKE), Faraday effect (FE) spectroscopy, and aiming to control spin-valley polarization with low magnetic fields. Whereas, in WP3, we are addressing the optical characterization of thin films or layers and heterostructures using modulation-free spectroscopic ellipsometry to extract thickness, refractive index, and dielectric response. These parameters are very crucial for understanding material quality and empowering device optimization. Module 2 will discuss on the development and implementation of experimental setups to achieve the proposed goals. We will build high-resolution, modulation-free CCD-based spectroscopic setups for ellipsometry, MOKE, and FE to perform faster, micron spatial resolution measurements of optical and magneto-optical phenomena in proposed materials. Furthermore, these homebuilt systems can be commercialized for the study of 2D quantum materials. In addition, 2DMMs and TMDC materials, including their heterostructures, will be fabricated using mechanical exfoliation in the laboratory of mentor Prof. Asish Arora at IISER Pune, and some of the crystals will be synthesized in collaboration across India. Overall, this proposal provides an understanding of fundamental physics in materials science and instrumentation development to advance the field of 2D quantum materials and their application in next-generation optoelectronic, spintronic, and valleytronic technologies.