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arXiv · 2207.08841

Large $N$ theory of critical Fermi surfaces II: conductivity

Haoyu Guo·Aavishkar A. Patel·Ilya Esterlis·Subir Sachdev
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Abstract

A Fermi surface coupled to a scalar field can be described in a $1/N$ expansion by choosing the fermion-scalar Yukawa coupling to be random in the $N$-dimensional flavor space, but invariant under translations. We compute the conductivity of such a theory in two spatial dimensions for a critical scalar. We find a Drude contribution, and verify that the proposed $1/\omega^{2/3}$ contribution to the optical conductivity at frequency $\omega$ has vanishing co-efficient for a convex Fermi surface. We also describe the influence of impurity scattering of the fermions, and find that while the self energy resembles a marginal Fermi liquid, the resistivity and optical conductivity behave like a Fermi liquid.

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Haoyu Guo, Aavishkar A. Patel, Ilya Esterlis, Subir Sachdev. 2022-07-18. Large $N$ theory of critical Fermi surfaces II: conductivity. https://doi.org/10.1103/physrevb.106.115151

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