Research Projects

The proposed project aims to investigate the emergence of topological transport phenomena, particularly the anomalous Hall effect (AHE) and topological Hall effect (THE), in collinear antiferromagnetic (AFM) oxide systems and their heterostructures. Despite the recent developments in the area of antiferromagnetic spintronics, until recently the anomalous Hall effect has not been associated with the antiferromagnetic materials. In collinear AFM and altermagnets, AHE signal arising in the non-relativistic limit of the electronic band structure provides pathway for the manifestation of dissipationless non-trivial topological transport. In the collinear AFM system various factors such as doping or charge transfer, strain state and symmetry breaking, spin-orbit coupling etc. can introduce canting of the moments. In such case, the origin of AHE can misunderstood and may result in anomaly in AHE that can be misinterpreted as THE. In this project, we aim to fabricate collinear antiferromagnetic based oxide heterostructures and derive intrinsic symmetry-driven AHE in the non-relativistic limit that is distinct from the canting of magnetic moments, charge transfer and spin-orbit effects. For this purpose we will also interface these materials with the strong SOC materials and understand the effect of SOC strength in modifying the electronic and transport properties of the systems under investigation. The scientific objectives of the project include (i) synthesizing and characterizing high-quality oxide thin films, heterostructures, and superlattices, (ii) disentangling the contributions of strain, Rashba SOC, and symmetry-driven effects to AHE and THE, and (iii) exploring the potential for engineering topological phases through strain and interfacial modifications. This work will primarily focus on oxide systems such as CaMnO₃, RuO₂, and LaMnO₃, leveraging their unique symmetry properties and the tunability of their structural and electronic characteristics. The heterostructures will be fabricated onto substrates offering the large range of lattice mismatch and onto the substrates with different crystal orientations. The project will employ advanced thin-film deposition techniques, comprehensive structural and spectroscopic characterization methods (including X-ray absorption spectroscopy and neutron reflectivity), and magnetotransport measurements under varying temperature and magnetic fields. This proposed research work lays a ground work to advance the device designs for antiferromagnetic spintronics. In fact, realization of anomalous Hall antiferromagnets based devices combine the functionalities of both ferromagnetic and antiferromagnetic spintronics i.e. ferromagnetic functionalities can now also be realized in the antiferromagnetic spintronics devises.