Logic circuits based on carbon nanotubes

We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. A new technique is used for achieving local gates in nanotube field-effect transistors that provide excellent capacitive coupling between the gate and nanotube, enabling the transistor to be ambipolar. The transistors show favorable device characteristics such as a high gain, a large on-off ratio, and room-temperature operation. Importantly, it also allows for the integration of multiple devices on a single chip. Indeed, we demonstrate 1-, 2-, and 3-transistor circuits that exhibit a wide range of digital logic operations such as an inverter, a logic NOR, and an AC ring oscillator.