YRLG Workshop: Correlation and Topology in magnetic materials, July 16th - 18th 2024
Chitraleema Chakraborty
Quantum degrees of freedom in flatland 2D materials are promising building blocks for quantum information processing, quantum communications, and quantum sensing. Optically active quantum defects in 2D materials, when compared to three-dimensional materials, have the advantage of reduced total internal reflection and easy coupling with interconnects. In this talk, I will share the story of the discovery and control of quantum emitters in two-dimensional materials. In particular, the possibility of leveraging van der Waals heterostructure for manipulating the electronic, optical and magnetic properties of emission from 2D semiconductors and magnetic heterostructure will be discussed. Optically active defects in TMDCs are highly sensitive to magnetic fields, providing an opportunity for direct probing of the layer-dependent 2D magnet's magnetic properties at the nanoscale. Layer-dependent 2D magnets, such as Chromium triiodide (CrI 3 ) and Chromium thiophosphate (CrPS 4 ), which display ferromagnetic (FM) and antiferromagnetic (AFM) properties depending on the layer count, have emerged as promising candidates for next- generation advanced spintronics devices. These materials offer improved speed (ranging from GHz to THz), electromagnetic interference immunity, and enhanced memory density due to their net-zero magnetization. However, their potential for future devices is hindered by challenges related to air stability and magnetic degradation of a few layers. While previous studies have classified the bulk form of these materials as AFM using the Magnetic Optical Kerr Rotation (MOKE) technique, the magnetic behavior of the surface layer of bulk CrPS 4 remains unexplored. We utilize proximity effect and spin polarized charge transfer in 2D magnetic heterostructures to probe the FM and AFM responses of the surface layers of bulk in these materials. These findings provide valuable insights into the potential applications of next- generation AFM-based spintronics and advanced memory-based devices. By harnessing the unique properties of AFM materials and 2D material-based emitters, this study contributes to the ongoing exploration of novel magnetic phenomena in heterostructures, facilitating advancements in spintronics and memory technology.