Quantum nanofriction in trapped ion chains with a topological defect

TL;DR

This paper investigates quantum effects in nanofriction within trapped ion chains featuring topological defects, highlighting quantum tunneling near the Aubry transition and proposing experimental conditions for observation.

Contribution

It introduces a simplified quantum model for the Aubry transition in ion chains with topological defects, emphasizing quantum tunneling effects near the critical point.

Findings

Quantum tunneling influences kink dynamics near the transition

Quantum effects are observable at low temperatures

Conditions for experimental detection are discussed

Abstract

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.