Research Projects

The proposed research aims to investigate voltage control of spin-orbit torques (SOTs) and Weyl points in kagome ferromagnet/heavy-metal heterostructures, with a focus on advancing low-power, high-efficiency spintronic applications. Kagome ferromagnets (e.g., Fe₃Sn₂, CoSn) possess a unique two-dimensional lattice geometry that leads to frustrated magnetism, strong spin-orbit coupling (SOC), and nontrivial topological band features such as flat bands, Dirac cones, and Weyl nodes. These materials exhibit giant anomalous Hall effects (AHE), low Gilbert damping, and chiral spin textures, making them ideal platforms for next-generation memory and logic devices. In ferromagnetic kagome systems interfaced with heavy metals, SOTs play a vital role in manipulating magnetization dynamics. Unlike conventional systems, kagome-based heterostructures can support unconventional SOTs with out-of-plane spin polarizations due to their symmetry-broken crystal and magnetic structures. Furthermore, voltage-controlled magnetic anisotropy (VCMA) has emerged as a promising tool to modulate SOTs and magnetic phases in a highly energy-efficient manner. This project will focus on synthesizing high-quality kagome FM thin films using ultra-high vacuum magnetron sputtering and optimizing their magnetic and electronic properties through controlled growth and post-annealing on various substrates. Emphasis will be placed on binary compounds of the form TmXₙ (T = Fe, Co; X = Sn, Pt), targeting tunable SOC strength, AHE, and PMA. Comprehensive structural and magnetic characterizations will be conducted using XRD, TEM, ferromagnetic resonance (FMR), and angle-resolved photoemission spectroscopy (ARPES) to map the topological band features. Next, voltage-gated micro-and nano-scale device architectures will be fabricated using optical and electron-beam lithography for spin-torque ferromagnetic resonance (ST-FMR) and second harmonic Hall effect measurements. These devices will be used to quantify the damping-like and field-like components of SOTs and analyze how applied gate voltages affect their magnitudes and orientations. Finally, voltage-controlled AHE studies will be integrated to evaluate how ferromagnetic ordering and topological responses evolve with gate bias. By systematically correlating voltage-tunable spin dynamics with band structure modifications, this work will advance fundamental understanding of topological spintronics in kagome systems and lay the groundwork for electrically reconfigurable spin-based devices.