Electrically tunable charge and spin transitions in Landau levels of interacting Dirac fermions in trilayer graphene

Trilayer graphene in the fractional quantum Hall effect regime displays a set of unique interaction-induced transitions that can be tuned entirely by the applied bias voltage. These transitions occur near the anticrossing points of two Landau levels. In a large magnetic field (>8 T) the electron-electron interactions close the anticrossing gap, resulting in some unusual transitions between different Landau levels. For the filling factor nu = 2/3, these transitions are accompanied by a change of spin polarization of the ground state. For small Zeeman energy, this provides a unique opportunity to control the spin polarization of the ground state by fine tuning the bias voltage.