Composite fermion dynamics in half-filled Landau levels of graphene

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We report on exact-diagonalization studies of correlated many-electron states in the half-filled Landau levels of graphene, including pseudospin (valley) degeneracy.

• We demonstrate that the polarized Fermi sea of non-interacting composite fermions remains stable against a pairing transition in the lowest two Landau levels.
• However, it undergoes spontaneous depolarization, which is unprotected owing to the lack of single-particle pseudospin splitting.
• These results suggest the absence of the Pfaffian phase in graphene.