Coulomb blockade in a single tunnel junction directly connected to a multiwalled carbon nanotube

We report on Coulomb blockade in a single tunnel junction directly connecte d to a multiwalled carbon nanotube (MWNT) by utilizing a nanoporous alumina film. The MWNT exhibits a weak localization effect with strong spin flip s cattering. Experimental results and analysis suggest that a high-impedance external environment caused by the weak localization in the MWNT can yield Coulomb blockade, in accordance with phase correlation theory in a single j unction system. It is also revealed that the Coulomb blockade is very sensi tive to phase modulation in the MWNT, which also acts as a high-impedance t ransmission line. (C) 2000 American Institute of Physics. [S0003-6951(00)01 939-2].