Band Structure of Carbon Nanotubes in a Perpendicular Electric Field - Version 2.0
NanoEd Resources - Online Lessons, Simulations and Games
Written by Umberto Ravaioli   
Thursday, 04 January 2007 13:38


This interactive simulator performs band structure calculations for zigzag and armchair type carbon nanotubes (CNT) using the nearest-neighbor tight-binding method with a hopping potential of - 2.5eV. Effects of curvature are not included in the model. A uniform electric field perpendicular to the axis can be applied, causing degenerate eigenvalues to split (Stark effect).

For each structure, the simulator performs eigenvalue solutions for 51 values of the quasi-momentum k, evenly spaced in the allowed range. The maximum CNT index is limited by memory allocation in the applet to n=30, corresponding to a (30,0) zigzag CNT and to a (30, 30) armchair CNT.

Notice that the user can obtain a solution for very small values of the index n, even n = 1. These solutions are for a strip of graphene sheet of width consistent with n and side periodic boundary conditions. Such hypothetical structures (n<5) are not practical but have educational value since they show how the band structure of the nanotube develops as n is increased (similar to building a crystal one atom at a time).

»» Start Band Structure Calculator


Yan Li, Slava V. Ralkin and Umberto Ravaioli
"Electric Response and Band Structure Modulation of Carbon Nanotubes in a Transverse Electric Field"
Nano Letters, vol 3, pp. 183-187, 2003.


Prof. Umberto Ravaioli

University of Illinois
at Urbana-Champaign
Urbana, IL USA


Last Updated on Thursday, 10 December 2009 15:27
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