Reentrant Metallic Behavior of Graphite in the Quantum Limit
  Magnetotransport measurements performed on several well-characterized highly oriented pyrolitic graphite and single crystalline Kish graphite samples reveal a reentrant metallic behavior in the basal-plane resistance at high magnetic fields, when only the lowest Landau levels are occupied. The results suggest that the quantum Hall effect and Landau-level-quantization-induced superconducting correlations are relevant to understand the metallic-like state(s) in graphite in the quantum limit. 
Y. Kopelevich, J. H. S. Torres, R. R. da Silva, F. Mrowka, H. Kempa,   P. Esquinazi