Room Temperature Spin Transport in Cd₃As₂

As the physical limits of CMOS loom closer, alternative state variable paradigms become increasingly important. Devices utilizing the electron spin as a state variable are especially promising due to their intrinsic non-volatility, speed, and versatility. Fully incorporating spintronic devices into next-generation computing systems requires optimized architectures and materials capable of efficiently harnessing the electron spin. One particularly promising class of materials are topological Dirac semimetals (TDS), exemplified by Cd₃As₂. TDS materials have high mobilities, 3D Dirac cones, and can exist in multiple quantum phases. We demonstrate the function of Cd₃As₂ as a channel for the flow of spin currents by incorporating it with hybrid graphene/MgO tunnel barriers as a non-local spin valve, the basic unit of spintronic devices for logic operations. We show that the spin valves operate at least up to room temperature.[1] We quantify the spintronic transport in the devices by measuring the spin Hall effect/inverse spin Hall effect, observing spin Hall angles up to θ_SH = 1.5 and spin diffusion lengths of 10-40 µm. Long spin-coherence lengths with efficient charge-to-spin conversion rates and coherent spin transport up to room temperature, as we show here in Cd₃As₂, are enabling steps toward realizing practical spintronic-based computing systems.