Structural solitons in carbon nanotubes
Carbon nanotubes (CNTs) have been subject of intense study since their discovery in 1991. Due to their remarkable physical properties, these one dimensional materials are promised to be a key player in many technological and scientific advances. While tight binding and zone-folding method methods of studying CNTs can provide qualitative physical pictures, more accurate predictions of their properties requires ab initio calculations. It is the purpose of our study to investigate the electronic properties of nanotubes subjected to axial tensions via Density Functional Theory (DFT) computations. We have done some preliminary calculations for CNTs subjected to tension using a DFT method where we observed some anomalies in electronic structure as function of strain. We saw that there is a drop in axial stress that is accompanied by a structural change which does not change the topology of the tube but forms soliton-like structure that is similar to polyacetylene. The strain at which this transition happens is a function of the diameter of the tube. Formation of these soliton-like structures can be related to electron-phonon coupling in this material. The purpose of our study to first find the origins of these anomalies and then quantify its impact on properties.