Dynamic admittance of carbon nanotube-based molecular electronic devices and theirequivalent electric circuit

Abstract

We use first-principles quantum mechanics to simulate the transient electrical responsethrough carbon nanotube-based conductors under time-dependent bias voltages. Thedynamic admittance and time-dependent charge distribution are reported and analyzed.We find that the electrical response of these two-terminal molecular devices canbe mapped onto an equivalent classical electric circuit and that the switchingtime of these end-on carbon nanotube devices is only a few femtoseconds. Thisresult is confirmed by studying the electric response of a simple two-site modeldevice and is thus generalized to other two-terminal molecular electronic devices.