Topological surface state electron transport in patterned SnTe films

We synthesize topological crystal insulator SnTe thin films with different patterns of polygon holes, polygon networks, and semiregular arrays of square holes. Magnetoconductivity on the patterned films shows that despite the presence of the holes, weak antilocalization (WAL) effects are present at all measured temperatures, from 2 to 10 K. Via fitting with the Hikami-Larkin-Nagaoka equation, a larger number of WAL channels at all temperatures in the patterned films compared to a flat continuous film was observed, suggesting the suppression of bulk conduction by the presence of the patterns. In the films patterned with square holes, the coherence length is limited to 200 nm at low temperatures (2 to 5 K), consistent with diffuse scattering of topologically protected surface state carriers to the hole boundaries. Our findings reveal opportunities to tune topological properties with nanopatterning.