抄録
Quantum dots have been fabricated in an individual single-wall carbon nanotube (SWCNT), and single electron transport measurements have been carried out at low temperatures. It is demonstrated that the SWCNT quantum-dot can be considered as an artificial atom where electrons are confined in a one-dimensional hard-wall potential. A shell structure and shell filling in magnetic fields are shown, and the excitation energy spectrum in magnetic fields was obtained for one or two electrons in a shell. A striking observation may be that quantum states of an interacting two-electron system were observed as singlet and triplet states which have energy difference at zero magnetic field. Reflecting energy scales associated with the SWCNT artificial atom, a quantum response to THz wave was, for the first time, observed in quantum dots as a photon assisted tunneling.
