Gate-controlled Tomonaga-Luttinger liquid and atomic-like behaviors in peapod quantum dots

摘要

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 C_(60) 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 C_(60) molecules do not directly contribute to the above quantum phenomena in peapods.