  Dissipation mechanisms are experimentally studied on topological insulator
surfaces of Bi2Te3, where common Joule dissipation was observed to be
suppressed due to topologically protected surface states. Thus, a novel type of
dissipation mechanism is observed by pendulum AFM, which is related to single
electron tunneling resonances into image potential states that are slightly
above the Bi2Te3 surface. The application of a magnetic field leads to the
break down of the topological protection of the surface states and restores the
expected Joule dissipation process. Nanomechanical energy dissipation
experienced by the cantilever of pendulum AFM provides a novel source of
information on the dissipative nature of the quantum-tunneling phenomena on the
topological insulator surface.
