Topological transistors with Weyl semiconductor for low-power computing

In the post-Moore era, electronics based on traditional materials face challenges such as heat dissipation, lack of stability against defects and environmental disturbances, and high power consumption. Topological materials are known for their robustness against defects and environmental disturbances, making them promising candidates for reliable informative electronic applications. Here, we have investigated the potential of using the Weyl semiconductor for developing functional field-effect transistors. Firstly, we present low-loss topological phase change transistors (TPCTs) based on tellurium (Te). The TPCTs utilize electrostatic gate modulation to control the energy separation between the Fermi level and the Weyl point, enabling a topological phase change between Weyl and conventional semiconductors. The TPCTs exhibit low-loss transport characteristics in the ON state, providing resistance against external disturbances, while demonstrating trivial charge transport in the OFF state by placing the Fermi level within the bandgap. At low operation voltage, these TPCTs exhibit the p-type transfer curve with 10⁸ ON/OFF ratio and ultrahigh ON-state conductance (39 mS/μm), a step forward for the development of p-type transistors. Additionally, we demonstrate room-temperature valley transistors in the non-local transport structure by manipulating the non-trivial band topology of Te. Te valley transistors generate long-lived valley polarization, as indicated by observed valley-polarized diffusion lengths, which overcomes the temperature limitation of short-lifetime valley-polarized excitons in previous works. By introducing the ion insertion/extraction, we have realized non-volatile synaptic states for neuromorphic computing with low readout power (~fW) and high recognition accuracy. Based on topological materials, we have realized functional topological field-effect transistors with analogue/digital computing, promising for post-Moore chips.