Shouvik Chatterjee: Controlling Hall response in epitaxial thin films of a Kagome antiferromagnet

Date: Friday, August 8th, 2025

Location: Elings Hall, room 1601

Time: 11:30 AM

Controlling Hall response in epitaxial thin films of a Kagome antiferromagnet

Abstract: Topological chiral antiferromagnets such as Mn3Sn are promising for spintronics due to their exotic magnetic and transport properties. In this talk, I will show that applying anisotropic strain in Mn3Sn thin films offers a novel route to control the magnetic ground state and unlock new functionalities. Strain lowers the symmetry of Mn Kagome triangles from C3v to C1, enabling a weak in-plane Dzyaloshinskii-Moriya interaction to cant Mn spins out of the Kagome plane. This leads to a state with finite scalar spin chirality, breaking time-reversal and mirror symmetries, and inducing a strong Berry curvature. As a result, a large anomalous Hall effect appears in the Kagome plane at room temperature. This strain-engineered ground state is two-fold degenerate, allowing realization of multi-stable, non-volatile Hall resistance memory states that are field-stable and electrically switchable under small bias fields – a property absent in bulk Mn3Sn. I will also discuss the evolution of magnetism in Mn3Sn/Ta bilayers, where a large topological Hall effect emerges, tunable via heat-assisted electrical switching.

Bio: Shouvik Chatterjee is a Reader at Tata Institute of Fundamental Research, Mumbai, India, where he leads an experimental group focusing on epitaxial synthesis and electron spectroscopy of quantum materials including Kagome metals, Sb square nets, and Kondo lattice compounds. He received his Ph.D. in condensed matter physics from Cornell University and worked as a post-doctoral scholar at the University of California, Santa Barbara