High Surface Conductivity of Fermi Arc Electrons in Weyl semimetals

Weyl semimetals (WSMs) have attracted great interest recently due to their unusual electronic states and intriguing transport properties. These systems are close cousins of topological insulators (TIs) which are known for their disorder tolerant surface states. Similarly, WSMs exhibit unique topologically protected Fermi arcs surface states. We have analyzed electron-phonon scattering as a function of the shape of the Fermi arc and find that the impact on surface transport disappears in the limit of a straight arc. Likewise, we have determined the effect of strong surface disorder on the resistivity by simulating a tight-binding model with the presence of quenched surface vacancies using the Coherent Potential Approximation (CPA) and Kubo-Greenwood formalism. We find that the limit of a straight arc is remarkably disorder tolerant, producing a surface conductivity 50 times larger than a comparable setup with surface states of TI. Finally I will discuss our simulations of the effects of surface vacancies on TaAs using the DFT + CPA method, illustrating the disorder tolerance of the topological surface states in a recently discovered WSM material.