Charge puddles in the bulk and on the surface of the topological insulator BiSbTeSe${}_2$ studied by scanning tunneling microscopy and optical spectroscopy

T. Knispel, W. Jolie, N. Borgwardt +6

The topological insulator BiSbTeSe${}_2$ corresponds to a compensated semiconductor in which strong Coulomb disorder gives rise to the formation of charge puddles, i.e., local accumu…