Measuring the Electron Beam Induced Plasmon Response in Single-Walled Carbon Nanotube Devices

In this work, we examine the transport properties of individual single-walled carbon nanotubes, configured with split gates, as it is excited by a finely focused electron beam. We conduct the experiment in a scanning electron microscope (SEM) equipped with multiple nanoprobes. We measure the current from both ends of the nanotube as the electron beam is rastered to determine the mechanism of transport. Our analysis shows that the energetic beam launches plasmon excitations along the nanotube, which we measure as a sharp change in the current. The sign of the current on both ends of the nanotube is the same, which rules out other competing mechanisms, including electron-hole generation and thermal effects. We examine the transport properties as a function of beam energy and position, and nanotube doping.