Quantum nanofriction in trapped ion chains with a topological defect

Trapped ion systems constitute a well controllable scenario for the study and emulation of nanofriction, and in particular of Frenkel-Kontorova-like models. This is in particular the case when a topological defect is created in a zigzag ion Coulomb crystal, which results in an Aubry transition from free sliding to pinned phase as a function of the trap aspect ratio. We explore the quantum effects of the Aubry transition by means of an effective simplified model, in which the defect is treated like a single quantum particle that experiences an effective Peierls-Nabarro potential and a position-dependent mass. We demonstrate the relevance of quantum tunneling in a finite range of aspect ratios close the critical point, showing that the quantum effects may be observed in the kink dynamics for sufficiently low temperatures. Finally, we discuss the requirements to reveal quantum effects at the Aubry transition in future experiments on trapped ions.

Automated summary

Trapped ion systems provide a well-controlled environment for studying and emulating nanofriction, particularly Frenkel-Kontorova-like models. By creating a topological defect in a zigzag ion Coulomb crystal, researchers observed an Aubry transition from free sliding to pinned phase, with quantum effects becoming relevant near the critical point. A simplified model treated the defect as a quantum particle with Peierls-Nabarro potential, revealing the importance of quantum tunneling in kink dynamics at low temperatures. Requirements for observing quantum effects at the Aubry transition in future trapped ion experiments were discussed.