Electron transport through double-walled carbon nanotube quantum dots

Electron transport through double-walled carbon nanotube quantum dots (DWCNT-QD) was calculated using full valence description of the electronic structure. Rolling pin model was used to measure the electron transport through both the walls of the DWCNT-QD. Three combinations of metallic (M) and zigzag semiconductor (S) nanotubes, i.e., M@S, S@M, and S@S, were studied for various diameters, and the corresponding I-V curves were obtained using the Landauer method. The transmission through the nanotubes was calculated using elastic scattering quantum chemistry (ESQC) method. A significant difference of 0.5 to 1.5 A in the current through the two walls of the DWCNT was found for the (4, 4)@(10, 9) and (5, 4)@(10, 9). In all other cases, the behavior of both the tubes in a DWCNT-QD was very similar to that of the corresponding single-walled carbon nanotube quantum dots (SWCNT-QD). The intermixing and correlation of the electronic states of the inner and outer shells of the DWCNTs responsible for such results were analyzed and discussed.