Spin-Polarized to Valley-Polarized Transition in Graphene Bilayers at $\nu =0$ in High Magnetic Fields

Abstract

We investigate the transverse electric field ($E$) dependence of the $\nu$=0 quantum Hall state (QHS) in dual-gated graphene bilayers in high magnetic fields. The longitudinal resistivity (${\rho }_{xx}$) measured at $\nu$=0 shows an insulating behavior which is strongest in the vicinity of $E$=0, and at large $E$-fields. At a fixed perpendicular magnetic field ($B$), the $\nu$=0 QHS undergoes a transition as a function of $E$, marked by a minimum, temperature-independent ${\rho }_{xx}$. This observation is explained by a transition from a spin polarized $\nu$=0 QHS at small $E$-fields, to a valley (layer) polarized $\nu$=0 QHS at large $E$-fields. The $E$-field value at which the transition occurs has a linear dependence on $B$

5 pages, 5 figures

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Cited by in corpus (4)

• The electronic properties of bilayer graphene
• Evidence for a Spin Phase Transition at ν=0 in Bilayer Graphene
• Magneto-optical and optical probes of gapped ground states of bilayer graphene
• Coexistence and competition of nematic and gapped states in bilayer graphene