One-dimensional nanostructures, such as nanowires and nanotubes play an
important role as fundamental building blocks for nano-electronics. In
particular, the predictable and controllable transport characteristics
would be critical to develop new nano-scale electronic devices. The
electrical measurements on individual nanowire and tube with the
mesoscopic non-magnetic or magnetic metal electrodes show that these
materials behave as the good conductor with long phase and spin coherence
length, p-type or n-type semiconductor depending on their crystal structure
and doping level. We have fabricated various kinds of nanodevices based on
nanowire and nanotube such as field effect transisor, hetero junction,
Schottky diode, spin device, and non-volatile memory device. The detailed
electron and spin transport characteristics of the nanodevices will be
presented.