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arXiv · 1808.04658

Elastic response of the electron fluid in intrinsic graphene: The collisionless regime

Julia M. Link·Daniel E. Sheehy·Boris N. Narozhny·Jörg Schmalian
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Abstract

The elastic response of an electron fluid at finite frequencies is defined by the electron viscosity $\eta(\omega)$. We determine $\eta(\omega)$ for graphene at the charge neutrality point in the collisionless regime, including the leading corrections due to the electron-electron Coulomb interaction. We find interaction corrections to $\eta(\omega)$ that are significantly larger if compared to the corresponding corrections to the optical conductivity. In addition, we find comparable contributions to the dynamic momentum flux due to single-particle and many-particle effects. We also demonstrate that $\eta(\omega)$ is directly related to the nonlocal energy-flow response of graphene at the Dirac point. The viscosity in the collisionless regime is determined with the help of the strain generators in the Kubo formalism. Here, the pseudo-spin of graphene describing its two sublattices plays an important role in obtaining a viscosity tensor that fulfills the symmetry properties of a rotationally symmetric system.

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Julia M. Link, Daniel E. Sheehy, Boris N. Narozhny, Jörg Schmalian. 2018-08-14. Elastic response of the electron fluid in intrinsic graphene: The collisionless regime. https://doi.org/10.1103/physrevb.98.195103

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