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arXiv · 1609.01448

Renormalization Group Approach to Stability of Two-dimensional Interacting Type-II Dirac Fermions

Ze-Min Huang·Jianhui Zhou·Shun-Qing Shen
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Abstract

The type-II Weyl/Dirac fermions are a generalization of conventional or type-I Weyl/Dirac fermions, whose conic spectrum is tilted such that the Fermi surface becomes lines in two dimensions, and surface in three dimensions rather than discrete points of the conventional Weyl/Dirac fermions. The mass-independent renormalization group calculations show that the tilting parameter decreases monotonically with respect to the length scale, which leads to a transition from two dimensional type-II Weyl/Dirac fermions to the type-I ones. Because of the non-trivial Fermi surface, a photon gains a finite mass partially via the chiral anomaly, leading to the strong screening effect of the Weyl/Dirac fermions. Consequently, anisotropic type-II Dirac semimetals become stable against the Coulomb interaction. This work provides deep insight into the interplay between the geometry of Fermi surface and the Coulomb interaction.

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Ze-Min Huang, Jianhui Zhou, Shun-Qing Shen. 2016-09-06. Renormalization Group Approach to Stability of Two-dimensional Interacting Type-II Dirac Fermions. https://doi.org/10.1103/physrevb.95.195412

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