Searching for the Fractional Quantum Hall Effect in Graphite

Y. Kopelevich (1) , Bertrand Raquet (2, 3) , Michel Goiran (2, 3) , Walter Escoffier (2, 3) , R.R. da Silva (1) , J.C. Medina Pantoja (1) , Igor A. Luk'Yanchuk (4) , A.A. Sinchenko (5) , Pierre Monceau (6)

1 Instituto de Fisica-Campinas
2 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble
3 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
4 LPMC - Laboratoire de Physique de la Matière Condensée - UR UPJV 2081
5 Moscow Engineering-Physics Institute
6 NEEL - MagSup - Magnétisme et Supraconductivité

Measurements of basal plane longitudinal rho(b)(B) and Hall rho(H)(dB) resistivities were performed on highly oriented pyrolytic graphite samples in a 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 holelike. 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. In addition, well-defined plateaus in rho(H)(B) were detected in the ultraquantum limit revealing possible signatures of the fractional quantum Hall effect in graphite.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Y. Kopelevich, Bertrand Raquet, Michel Goiran, Walter Escoffier, R.R. da Silva, et al.. Searching for the Fractional Quantum Hall Effect in Graphite. Physical Review Letters, 2009, 103 (11), pp.116802. ⟨10.1103/PhysRevLett.103.116802⟩. ⟨hal-00966951⟩