The effect of magnetic and non-magnetic ion damage on the surface state in SmB6

• SmB6 single crystal surfaces were damaged with magnetic Fe ions.
• Conductive surface state was not destroyed by the damage.
• Surface state reconstructs below the damage as seen with non-magnetic ion damage.
• Low concentration non-magnetic ion damage moderately increases surface resistivity.

SmB6 is a Kondo insulator with a band structure that is topologically distinct from the vacuum. This is theoretically predicted to produce metallic topological surface states that are robust to perturbations that do not break time reversal symmetry, such as non-magnetic defects. However, the surface state may be destroyed by an impurity with a sufficiently large magnetic moment. In order to test this prediction we show measurements of the resistance of the surface state of single crystals of SmB6 with varying levels of damage induced by magnetic and non-magnetic ion irradiation. We find that at a sufficiently high concentration of damage the surface state reconstructs below an amorphous damaged layer, whether the damage was caused by a magnetic or non-magnetic ion.