High-Tc superconductivity in entirely end-bonded carbon nanotubes

One-dimensional (1D) systems face some obstructions that may prevent the emergence of superconductivity(SC), e.g., a Tomonaga-Luttinger liquid (TLL) and Peierls transition. A carbon nanotube (CN) is one of the best candidates for investigating a possibility of 1D SC and its interplay with such obstructions. Only two groups have experimentally reported SC in ropes of single-walled CNs (SWNTs) and very thin SWNTs [1] to date. In addition, those interplay with 1D phenomena have never been clarified. Some theoretical papers also predicted strong correlation between TLL states and SC for SWNT ropes and importance of electron-phonon interaction for thin SWNTs [2]. Here, we report that entirely end-bonded multi-walled CNs (MWNTs) can show SC with the T$_{c}$ as high as 12K [3] (about 50-times larger than T$_{c}$ in former of [1]). We find that emergence of this SC and its interplay with TLL states are highly sensitive to junction structures of Au electrode/MWNTs. Only MWNTs with optimal numbers of electrically activated shells realized by the entire end-bonding can allow the SC due to intershell effects. \textbf{Refs.} \textbf{1.}M. Kociak, et al., PRL 86, 2416 (2001); Z. K. Tang, et al., Science 292, 2462 (2001), \textbf{2}.J.Gonzalez, PRL 88, 076403 (2002); R.Barnett, et al., PRB 71, 035429 (2005), \textbf{3}.J.Haruyama et al., PRL Accepted