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arXiv · 0812.0403

Graphene magnetoresistance in a parallel magnetic field: Spin polarization effect

E. H. Hwang·S. Das Sarma
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Abstract

We develop a theory for graphene magnetotransport in the presence of carrier spin polarization as induced, for example, by the application of an in-plane magnetic field ($B$) parallel to the 2D graphene layer. We predict a negative magnetoresistance $σ\propto B^2$ for intrinsic graphene, but for extrinsic graphene we find a non-monotonic magnetoresistance which is positive at lower magnetic fields (below the full spin-polarization) and negative at very high fields (above the full spin-polarization). The conductivity of the minority spin band $(-)$ electrons does not vanish as the minority carrier density ($n_-$) goes to zero. The residual conductivity of $(-)$ electrons at $n_- = 0$ is unique to graphene. We discuss experimental implications of our theory.

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E. H. Hwang, S. Das Sarma. 2008-12-02. Graphene magnetoresistance in a parallel magnetic field: Spin polarization effect. https://doi.org/10.1103/physrevb.80.075417

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