Coulomb Oscillations and Hall Effect in Quasi-2D Graphite Quantum Dots

We perform low-temperature electrical transport measurements on gated, quasi-2D graphite quantum dots. In devices with low contact resistances, we use longitudinal and Hall resistances to extract carrier densities of 9.2−13 × 1012 cm-2 and mobilities of 200−1900 cm2/V·s. In devices with high resistance contacts, we observe Coulomb blockade phenomena and infer the charging energies and capacitive couplings. These experiments demonstrate that electrons in mesoscopic graphite pieces are delocalized over nearly the whole graphite piece down to low temperatures.