Papers by Author: I. Takesue

Abstract: Anomalously high values of power α (1.6 < α < 12) are found in power laws in conductance versus energy relationships in carbon-nanotube peapod quantum dots, encapsulating a chain of C60 molecules. This power is controllable by the applied back gate voltage. Atomic-like behaviors with doubly degenerate ground states are also found by single electron spectroscopy. They reveal that a portion of power originates from the Tomonaga-Luttinger liquid via the occupied electronic levels, which originate from the subbands unique to the peapods. This observation also clarify that the encapsulated C60 molecules do not directly contribute to the above quantum phenomena in peapods.

Abstract: We report that entirely end-bonded multi-walled carbon nanotubes (MWNTs) within Tomonaga-Luttinger liquid (TLL) states at high temperatures can show superconductivity with the transition temperature Tc as high as 12K that is approximately 40-times larger than those in ropes of single-walled nanotubes. We find that emergence of this superconductivity is very sensitive to junction structures of Au electrode/MWNTs. This indicates that MWNTs with optimal numbers of electrically activated shells can allow the superconductivity that overcomes the TLL sates, due to intershell effects.