Double Fermi arcs in charge-compensated and charge-uncompensated Na₃Bi slabs.

Na₃Bi is a topological Dirac semimetal [1] which can support double surface Fermi arcs [1-3]. Angle resolved photoemission spectroscopy (ARPES) measurements on Na₃Bi's (100) facet are consistent with double surface Fermi arcs [4]. However, these arcs are not topologically protected by all symmetry-preserving bulk perturbations [5] or surface effects [2]. It is currently unknown whether realistic perturbations and surfaces can destroy the Fermi arcs.

We consider realistic tight-binding models of Na₃Bi derived from first principles calculations. To investigate the effects of realistic surface and bulk conditions, we consider two surface terminations: one which is lower energy and charge-compensated, likely representative of experimental conditions, and one that is higher energy and charge-uncompensated with trivial surface states. We find that Fermi arcs coexist with trivial surface states even in the higher energy surface.

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2. A. C. Potter, I. Kimchi, and A. Vishwanath, Nature Communications 5, 5161 (2014).

3. E. V. Gorbar, V. A. Miransky, I. A. Shovkovy, and P. O. Sukhachov, Phys. Rev. B 91, 121101 (2015).

4. S.-Y. Xu, et al, Science 347 (2015).

5. M. Kargarian, M. Randeria, and Y.-M. Lu, Proceedings of the National Academy of Sciences 113 (2016).