AC Conductance of Finite-length Carbon Nanotubes

TL;DR

This paper introduces a nonequilibrium Green's function method to analyze the ac conductance of finite-length carbon nanotubes, revealing significant differences from infinite-length cases and oscillatory behavior dependent on various nanotube properties.

Contribution

It presents a novel approach to calculate ac conductance in finite-length carbon nanotubes and explores how length, helicity, and defects influence conductance oscillations.

Findings

Finite-length nanotubes show distinct ac conductance profiles from infinite ones.

Quantized conductance peaks are observable at low frequencies in finite nanotubes.

Conductance oscillates with ac frequency depending on nanotube properties.

Abstract

We propose a nonequilibrium Green's function approach to calculate the ac conductance of various finite-length carbon nanotubes. The simulated ac conductance differs significantly from that of the infinite-length ones. At the low-frequency limit, the profiles of the quantized conductance are still observable in the finite-length carbon nanotubes, but many more peaks appear on the conductance curves. We also show that the conductance of finite-length carbon nanotubes will oscillate as a function of the ac frequency. The dependence of the oscillation on the lengths, helicities and defects of the carbon nanotubes are also investigated. The knowledge we gain from this research will help us make carbon-nanotube-based interconnects or other ac devices in the future