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arXiv · 2210.06641

Dynamical Effects from Anomaly: Modified Electrodynamics in Weyl Semimetal

Xuzhe Ying·A. A. Burkov·Chong Wang
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Abstract

We discuss the modified quantum electrodynamics from a time-reversal-breaking Weyl semimetal coupled with a $U(1)$ gauge (electromagnetic) field. A key role is played by the soft dispersion of the photons in a particular direction, say $\hat{z}$, due to the Hall conductivity of the Weyl semimetal. Due to the soft photon, the fermion velocity in $\hat{z}$ is logarithmically reduced under renormalization group flow, together with the fine structure constant. Meanwhile, fermions acquire a finite lifetime from spontaneous emission of the soft photon, namely the Cherenkov radiation. At low energy $E$, the inverse of the fermion lifetime scales as $\tau^{-1}\sim E/{\rm PolyLog}(E)$. Therefore, even though fermion quasiparticles are eventually well-defined at very low energy, over a wide intermediate energy window the Weyl semimetal behaves like a marginal Fermi liquid. Phenomenologically, our results are more relevant for emergent Weyl semimetals, where the fermions and photons all emerge from strongly correlated lattice systems. Possible experimental implications are discussed.

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Xuzhe Ying, A. A. Burkov, Chong Wang. 2022-10-13. Dynamical Effects from Anomaly: Modified Electrodynamics in Weyl Semimetal. https://doi.org/10.1103/physrevb.107.035131

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