Dissolution of topological Fermi arcs in a dirty Weyl semimetal

Weyl semimetals (WSMs) have attracted much attention recently as they provide for a condensed matter realization of a chiral anomaly, feature topologically protected Fermi arc surface states, and sustain sharp chiral Weyl quasiparticles up to a critical disorder at which a continuous quantum phase transition (QPT) drives the system into a metallic phase. We present numerical results that demonstrate that the Fermi arc gradually loses its sharpness upon increasing disorder, resulting in the dissolution of the arc into the metallic bath of the bulk close to the WSM-metal QPT [1]. These results verify the predicted topological nature of the WSM-metal QPT and the corresponding bulk-boundary correspondence across the transition. Moreover, by following the continuous deformation of the Fermi arcs with increasing disorder in discovered Weyl materials, this effect should be directly discernible in angle-resolved photoemission spectroscopy (ARPES) and Fourier transformed scanning tunneling microscopy (STM) measurements.

[1] R.-J. Slager, V. Juricic, and B. Roy, Phys. Rev. B 96, 201401(R) (2017).