Nanofriction and motion of topological defects in self-organized ion Coulomb crystals

Kiethe, Jan; Nigmatullin, Ramil; Schmirander, T.; Kalincev, D.

doi:10.1088/1367-2630/aaf3d5

Cited by 15 publications

(9 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here the soft mode of the pinning to sliding transition exhibited a finite frequency at the critical point, when a finite temperature allowed the system to switch between different minima of the Peierls-Nabarro potential [12,61].…”

Section: Discussionmentioning

confidence: 99%

Finite temperature spectrum at the symmetry-breaking linear-zigzag transition

Kiethe,

Timm,

Landa

et al. 2020

Preprint

View full text Add to dashboard Cite

We investigate the normal mode spectrum of a trapped ion chain at the symmetry-breaking linear to zigzag transition and at finite temperatures. For this purpose we modulate the amplitude of the Doppler cooling laser in order to excite and measure mode oscillations. The expected mode softening at the critical point, a signature of the second-order transition, is not observed. Numerical simulations show that this is mainly due to the finite temperature of the chain. Inspection of the trajectories suggest that the thermal shifts of the normal-mode spectrum can be understood by the ions collectively jumping between the two ground state configurations of the symmetry broken phase. We develop an effective analytical model, which allows us to reproduce the low-frequency spectrum as a function of the temperature and close to the transition point. In this model the frequency shift of the soft mode is due to the anharmonic coupling with the high frequency modes of the spectrum, acting as an averaged effective thermal environment. Our study could prove important for implementing ground-state laser cooling close to the critical point.

show abstract

Section: Discussionmentioning

confidence: 99%

Finite temperature spectrum at the symmetry-breaking linear-zigzag transition

Kiethe,

Timm,

Landa

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Systems of optically trapped Brownian particles, where the local temperature can be controlled by modulating the trapping laser, have been experimentally studied in [34,35]. Experimentally, the FK potential (1) has been used to describe coulomb crystals of ions in optical lattices [9][10][11][12]. In particular, in [9] the authors were able to control the nanofriction at the individual-atom level.…”

Section: Discussionmentioning

confidence: 99%

“…On the experimental side, the FK model has been realized by using chains of ions in optical lattices [9][10][11][12], and there has been a recent proposal to realize the model by using Ryndberg atoms [13].…”

Section: Introductionmentioning

confidence: 99%

Out-of-equilibrium Frenkel-Kontorova model

Imparato

2020

Preprint

View full text Add to dashboard Cite

A 1D model of interacting particles moving over a periodic substrate and in a position dependent temperature profile is considered. When the substrate and the temperature profile are spatially asymmetric a center-of-mass velocity develops, corresponding to a directed transport of the chain. This autonomous system can thus transform heath currents into motion. The model parameters can be tuned such that the particles exhibit a crossover from an ordered configuration on the substrate to a disordered one, the maximal motor effect being reached in such a disordered phase. In this case the manybody motor outperforms the single motor system, showing the great importance of collective effects in microscopic thermal devices. Such collective effects represent thus a free resource that can be exploited to enhance the dynamic and thermodynamic performances in microscopic machines.

show abstract

“…Crucially, due to the presence of the defect, the axial distance in the upper and lower subchains differ. As a result, the kink emulates an incommensurate interface of two particle chains, whose influence on one another is determined by the Coulomb repulsion [34]. For low values of α the defect is captured in the trap center due to its repulsion from the crystal boundaries [36].…”

Section: Aubry Transitionmentioning

confidence: 99%

“…Nanofriction has then been characterized by the forces necessary to dislocate the particles, revealing the absence of a friction force in the sliding regime. A different setup emulates Aubry physics in a self-organized system, that is the two sub-chains of an ion crystal under the presence of a topological defect, which provides the necessary incommensurability between the length scales of the subchains [33,34]. Experiments on this approach have demonstrated the softening of a motional mode at the transition point by measuring its resonance frequency.…”

Section: Introductionmentioning

confidence: 99%

Quantum nanofriction in trapped ion chains with a topological defect

Timm,

Rüffert,

Weimer

et al. 2021

Preprint

View full text Add to dashboard Cite

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.

show abstract

Nanofriction and motion of topological defects in self-organized ion Coulomb crystals

Cited by 15 publications

References 54 publications

Finite temperature spectrum at the symmetry-breaking linear-zigzag transition

Finite temperature spectrum at the symmetry-breaking linear-zigzag transition

Out-of-equilibrium Frenkel-Kontorova model

Quantum nanofriction in trapped ion chains with a topological defect

Contact Info

Product

Resources

About