  Excess conductance fluctuations with peculiar temperature-dependence from 1.4
to 250 K were observed in curved nano-graphite sheets with an electrode gap
length of 300 and 450 nm, whereas the conductance fluctuation is greatly
suppressed above 4.2 K when the electrode gap length increases to 800 and 1000
nm. The former is discussed in the context of the presence of a small energy
bandgap in the nano-graphite sheets, while the latter is attributed to the
crossover from coherent transport to diffusive transport regime.
