Heat transport in an ion Coulomb crystal with a topological defect

The thermodynamics of low-dimensional systems departs significantly from phenomenologically deducted macroscopic laws. Particular examples, not yet fully understood, are provided by the breakdown of Fourier's law and the ballistic transport of heat. Low-dimensional trapped ion systems provide an experimentally accessible and well-controlled platform for the study of these problems. In our paper, we study the transport of thermal energy in low-dimensional trapped ion crystals, focusing, in particular, on the influence of the Aubry-like transition that occurs when a topological defect is present in the crystal. We show that the transition significantly hinders efficient heat transport, being responsible for the rise of a marked temperature gradient in the nonequilibrium steady state. Further analysis reveals the importance of the motional eigenfrequencies of the crystal.