Nanofriction and motion of topological defects in self-organized ion Coulomb crystals
J. Kiethe, R. Nigmatullin, T. Schmirander, D. Kalincev and T. E. Mehlstäubler
Recently, we presented a model system for nanofriction consisting of an ion Coulomb crystal with a topological defect. In this system we investigated the transition between the pinning and sliding regime of friction. We observed signatures of this transition, i.e. a symmetry breaking of the crystal structure and the existence of a soft mode.
In a new publication we discuss the influence of external potentials, like anharmonic trapping potentials and differential light pressure, on these signatures. We show that the topological defect mode has an exceptional sensitivity to these potentials near the transition. We also present an analysis on how the properties of the defect change as it is moved through the ion Coulomb crystal. The results have been published in New Journal of Physics: