Multislip Friction with a Single Ion

Abstract

A trapped ion transported along a periodic potential is studied as a paradigmatic nanocontact frictional interface. The combination of the periodic corrugation potential and a harmonic trapping potential creates a one-dimensional energy landscape with multiple local minima, corresponding to multistable stick-slip friction. We measure the probabilities of slipping to the various minima for various corrugations and transport velocities. The observed probabilities show that the multislip regime can be reached dynamically at smaller corrugations than would be possible statically, and can be described by an equilibrium Boltzmann model. While a clear microscopic signature of multislip behavior is observed for the ion motion, the frictional force and dissipation are only weakly affected by the transition to multistable potentials. DOI: 10.1103/PhysRevLett.119.043601 Stick-slip friction is a ubiquitous nonequilibrium dynamical process that occurs at the interface between surfaces across a wide range of length scales [1][2][3][4][5][6]. The term stick slip describes the system's response to an applied shear force: the surfaces slip out of a local minimum in the interface energy landscape, and stick into a new lowerenergy minimum, releasing heat in the process.Recent advances in atomic force microscopy (AFM) have extended the study of stick-slip friction to the atomic scale, where atom-by-atom slips occur at the interface between a probe tip and a periodic substrate [7][8][9][10][11][12][13][14][15][16][17][18]. For a single-atom probe, the number of local minima in the probe-substrate interaction potential is determined by the ratio of the periodic substrate potential to the spring constant with which the probe is bound to its support object. As the load on the probe is increased, or equivalently, the periodic substrate potential is deepened, the system transitions from a bistable regime (where the probe deterministically single slips from the first minimum to the second) to a multistable regime (where a probe can stochastically multislip to one of several local minima). This has been demonstrated in AFM simulations [19][20][21][22] and experiments [23][24][25] where single-slip and multislip events have been clearly differentiated. However, in the absence of control over dissipation rates and the microscopic energy landscape, it is difficult to tie the observations to ab initio friction models.Following theoretical proposals [26][27][28][29], we have recently demonstrated a trapped-ion friction emulator with extensive control over all microscopic interface parameters [30][31][32]. In analogy to AFM, the emulator features a small probe (one or several trapped ions) transported over a In this Letter, we study multislip friction in deep substrate potentials. We observe the ion fluorescence associated with slip events, from which we directly extract the temperature-and velocity-dependent probabilities for the ion to localize in one of the available local minima. We find that at finite rethermalization times following a s...

Kinks and nanofriction: Structural phases in few-atom chains

“…1, diamond 2) where p k ∼ p 0 and the slips are asynchronous, friction is low. The transition point p c also marks a reduction in the dependence of friction F s on the misfit p 0 , thus Fmax is the maximal friction in the single-slip regime [29,30].…”

“…Such emulators [18][19][20] have been used to observe the Aubry transition [21][22][23] and kink transport [16,24]. Cold trappedion systems [25][26][27][28] have been used to study fundamental aspects of atomistic friction, such as mismatch-induced lubricity [17], the temperature and velocity dependence of friction [29], and multislip friction [30].…”

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

“…the Frenkel-Kontorova (FK) model [10], using ion chains in an optical lattice [11][12][13]. Following the proposals, Bylinskii et al were able to trap 5 ions in an optical lattice, demonstrating the onset of reduced friction [14], the velocity dependence of the stick-slip motion [15], as well as single ion multi-slip behavior [16]. Furthermore, they observed structural symmetry-breaking at the pinning to sliding transition [17], an Aubry-type (AT) transition.…”

Static and dynamic phases of a Tonks–Girardeau gas in an optical lattice

“…Quantum phase transitions in these systems can be probed by switching the control parameter across a critical point [13][14][15][16][17][18]. Additionally, the transport properties of such systems can be linked to classical models of friction which describe stick-slip motion between two surfaces [19][20][21][22][23], an effect which has been recently observed [24][25][26]. In fact, precise control of the competing length scales between the two surfaces can be used to effectively control the amount of friction present [27] and can give insights into designing frictionless dynamical processes for quantum systems.…”