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arXiv · 1906.07756

Superconductivity in Graphene Induced by the Rotated Layer

D. Schmeltzer
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Abstract

Recent discoveries in graphene bilayers revealed that when one of the layers is rotated, superconductivity emerges. We provide an explanation for this phenomenon . We find that due to the layer rotations, the spinors are modified in such way that a repulsive interaction, becomes attractive in certain directions. This result is obtained following a sequence of steps: when layer $2$ is rotated by an angle $θ$ ,this rotation is equivalent to a rotation of an angle $-θ$ of the linear momentum .Due to the discreet lattice, in layer $1$, the Fourier transform conserves the linear momentum $modulo$ the hexagonal reciprocal lattice vector . In layer $2$, due to the rotation, the linear momentum is conserved $modulo$ the $Moire$ reciprocal lattice vector . Periodicity is achieved at the $magical $ angles obtained from the condition of commensuration of the two lattices. We find that the rotations transform the spinors around the nodal points, such that a repulsive interaction becomes attractive, giving rise to superconductivity.

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D. Schmeltzer. 2019-06-18. Superconductivity in Graphene Induced by the Rotated Layer. https://doi.org/10.1016/j.aop.2020.168305

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