TRANSPORT SPECTROSCOPY OF SINGLE-WALLED CARBON NANOTUBES

We have performed transport spectroscopy on individual ropes of single -walled carbon nanotubes. We find that the levels are Zeeman split in a magnetic held, with a g-factor of 2.04 +/- 0.05. The observed patter n of peak splittings indicates the parity of the number of electrons o n the dot. In one device there are also signs of the presence of a sec ond dot. We observe features which resemble anticrossings between quan tum levels in the two dots, which may be formed from separate conducti ng nanotubes within the rope. (C) 1998 Elsevier Science B.V. All right s reserved.