Topological Quantum Materials

This effect manifests in the presence of a low temperature and an external magnetic field, which is why researchers sought to explore topologically protected materials without relying on an external magnetic field, leading to the emergence of discoveries in topological materials. 

Topological materials are materials having the unique properties of insulating bulk, metallic surface states, and high spin-orbit coupling. Hence, the role of a magnetic field is played by the fictitious field produced by this large spin-orbit coupling. A large spin-orbit coupling leads to band inversion, which leads to the development of surface states connecting the valence and conduction bands. A normal metallic state treats an up-and-down spin equally but when it comes to surface metallic states, these have separate channels for up-and-down spins. This has a very useful consequence of spin-momentum-locking found in topological materials that facilitates long spin lifetime, spin manipulation, efficient spin-transport, topological protection, and spin-based quantum technologies

Our publications in this area:

1. Kagome Magnets: The Emerging Materials for Spintronic Memories, Niru Chowdhury, Kacho Imtiyaz Ali Khan, Himanshu Bangar, Pankhuri Gupta, Ram Singh Yadav, Rekha Agarwal, Akash Kumar, and Pranaba Kishor Muduli. Proc. Natl. Acad. Sci., India, Sect. A Phys. Sci., 93, 477 (2023).

2. Intrinsic anomalous Hall effect in thin films of topological kagome ferromagnet Fe3Sn2,  Kacho Imtiyaz Ali Khan,  Ram Singh Yadav, Himanshu Bangar, Akash Kumar, Niru Chowdhury, Prasanta Kumar Muduli, and Pranaba Kishor Muduli, Nanoscale, 14, 8484 (2022).