AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Thursday Sessions
       Session NS-ThM

Invited Paper NS-ThM1
Quantum-dot Nanodevices with Carbon Nanotubes

Thursday, November 3, 2005, 8:20 am, Room 210

Session: Nanotube-based Devices
Presenter: K. Ishibashi, RIKEN, Japan
Authors: K. Ishibashi, RIKEN, Japan
S. Moriyama, RIKEN, Japan
T. Fuse, RIKEN, Japan
D. Tsuya, RIKEN, Japan
M. Suzuki, RIKEN, Japan
Correspondent: Click to Email
Carbon nanotubes are attractive building blocks for extremely small nanodevices. In this paper, we present our effort to fabricate and demonstrate quantum-dot nanodevices, which includes following topics. 1) Single electron devices: A single electron transistor (SET), a single electron inverter that is consisting of two SETs in series, and a single electron XOR that has two input gates to SET, are fabricated in individual single-wall carbon nanotubes (SWCNTs) or multi-wall carbon nanotubes (MWCNTs), and their operation was demonstrated. 2) Quantum computing device (Qubit) and an artificial atom in the SWCNT: We focus on the spin qubit in association with observations of the artificial-atom like behavior. It is shown that the four or two electron shell structure was observed in single electron transport measurements at milli-Kelvin temperatures, and the shell filling of successive electrons and the Zeeman splitting of single particle states were confirmed in the magnetic field evolution of each Coulomb peak. The simple singlet and triplet states were directly observed in excitation spectroscopy measurements when two electrons were contained in a shell. These observations show that the SWCNT is very similar to natural atom with its unique shell structure and an energy scale of submillimeter to THz ranges. Despite the demonstrated wonderful properties as a building block of the nanodevices, we should admit that a breakthrough of device processes suitable for carbon nanotubes is really needed to realize more reliable and reproducible nanodevices.