Absence of surface states for LiFeAs investigated using density functional calculations

We investigate the cleaving behavior of LiFeAs and determine its surface electronic structure by detailed density functional calculations. We show that due to the neutral surface of LiFeAs after cleaving, barely any influence of the surface on the electronic states is present. Therefore the data of surface sensitive probes such as angle-resolved photoemission spectroscopy (ARPES) represent to a high degree the bulk electronic structure. This we highlighted by a direct comparison of the calculations to ARPES spectra.

Figure 1

Interlayer distances of LiFeAs as a function of tensile strain in $z$ direction. The lines between data points are guides for the eye.

Figure 2

(Color online) Band structure of bulk LiFeAs, orbital projected onto the leading Fe, As, and Li orbitals.

Figure 3

(Color online) Band plot of bulk LiFeAs for $k_z=0$ (black) and $k_z=\pi$ (red or dark gray) and slab LiFeAs (green or light gray lines).

Figure 4

(Color online) FS of LiFeAs. The $Z$ point is above $\Gamma$, the A point above M and, the R point above X. Left panel: bulk. Right panel: slab (no $z$ dispersion; 3D perspective for better visibility only).

Figure 5

(Color online) FS of a LiFeAs from angle-resolved photoemission.

Figure 6

(Color online) Upper panel: photoemission intensity recorded along the high-symmetry directions in LiFeAs. Lower panel: corresponding results for the calculated bulk band structure.