In-gap states on the non-polar (110) surface of SmB$_{6}$

Mixed-valent SmB$_6$ with a temperature-dependent bulk gap is the first candidate example of a new class of strongly correlated topological insulators with $f$-$d$ band inversion. The topological origin of in-gap states on cleaved (001) surfaces as measured by angle-resolved photoemission (ARPES) is not without controversy, since the $\overline{X}$ states span the full $\sim$20 meV hybridization gap at low temperature without exhibiting any clear Dirac point. Furthermore, reports exist of band-bending due to the polarity of the (001) surface and depth-dependent deviations from bulk stoichiometry or Sm valency. In this work we explore ARPES of the $non$-$polar$ (110) surface of SmB$_6$ prepared by polishing and high-temperature annealing. We find in-gap states at $\overline{X}$ and $\overline{Y}$ points with very similar properties as the (001) $\overline{X}$ states. We discuss the relevance of these findings to the TI and other proposed models, and to the recent discrepancy between 2D [1] and 3D [2] interpretations of dHvA Fermi surface orbits.\newline [1] G. Li, $et\ al.$, Science \textbf{346}, 1208 (2014).\newline [2] B.S. Tan, $et\ al.$, Science \textbf{349}, 287 (2015).