Possible Fractional Quantum Hall Effect in Graphite

Authors :: Kopelevich, Y.
Raquet, B.
Goiran, M.
Escoffier, W.
da Silva, R. R.
Pantoja, J. C. Medina
Lukyanchuk, I. A.
Sinchenko, A.
Monceau, P.
Publication Year :: 2009
Publisher :: arXiv, 2009.
Abstract: Measurements of basal plane longitudinal rho_b(B) and Hall rho_H(B) resistivities were performed on highly oriented pyrolytic graphite (HOPG) samples in pulsed magnetic field up to B = 50 T applied perpendicular to graphene planes, and temperatures 1.5 K < T < 4.2 K. At B > 30 T and for all studied samples, we observed a sign change in rho_H(B) from electron- to hole-like. For our best quality sample, the measurements revealed the enhancement in rho_b(B) for B > 34 T (T = 1.8 K), presumably associated with the field-driven charge density wave or Wigner crystallization transition. Besides, well defined plateaus in rho_H(B) were detected in the ultra-quantum limit revealing the signatures of fractional quantum Hall effect in graphite.<br />15 pages, including 4 figures