ACCESS · Engineering Spin-Splitting in Atomically Thin 2D Non-Centrosymmetric Crystals

The information technology and communication sector (ICT) has been undergoing remarkable progress fuelled by integrational advancements in its building blocks, the field effect transistor (FET). The FETs in commercials microprocessors still use more than half a century old energy-intensive conductance switching processes to perform logic operations. It is well understood that the inability to remove the dissipated energy in such switching process will eventually stop the ongoing downscaling of the microprocessors in the next few years. Spintronic-based devices, working by virtue of energy efficient switching the spin-polarization, are considered to bring a paradigm shift in logic operations. Such devices use charge-to-spin interconversion (CSI) which is maximized in materials with strong spin-orbit coupling (SOC). The main goal of ACCESS is to engineer inversion symmetry and SOC in vertical heterostructures of two-dimensional layered materials (2DLMs) to facilitate the CSI process. We shall fabricate dual gated hBN encapsulated FETs using the 1T' phase of transitional metal dichalcogenides and its twisted bilayers to tune symmetry and SOC. ACCESS will exploit the Edelstein effect and intrinsic Berry curvature dipole to generate current-induced magnetization and detect it via unidirectional magnetoresistance (UMR) and nonlinear Hall effect (NHE) measurements. The CSI in our samples will be further tuned by dynamically varying vertical displacement field and the charge carrier density in the channel. By this way, ACCESS will harness the topological properties of 2DLMs for applications in future spintronics devices, capable of magnet-free spin-to-charge interconversion. Besides its scientific goals, ACCESS also focuses on strengthening the researcher’s transferable skills and providing him a high-quality interdisciplinary research training, helping him to build a promising scientific research career.