Artificial atom and quantum terahertz response in carbon nanotube quantumdots

Abstract

Artificial atom behaviours have been observed in single-wall carbon nanotube (SWCNT)quantum dots (QDs). Two-electron shell structures and the Zeeman splitting ofsingle-particle states were revealed in single-electron transport measurements in lowtemperatures. To demonstrate that the charging energy of the dot lies in a terahertz (THz)range, the THz photon-assisted tunnelling was tested, and was really observed as a satelliteCoulomb peak. Some satellite peaks moved as a frequency was changed, but other peaksdid not move. We give possible models to explain the existence of two different satellitepeaks.