Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How do cold ions slide?

27.05.2013
Exploring friction by simulating toy-like systems

Things not always run smoothly. It may happen, actually, that when an object slides on another, the advancement may occur through a 'stop and go' series in the characteristic manner which scientists call "stick-slip", a pervasive phenomenon at every scale, from earthquakes to daily-life objects, up to the "nano" dimension.


This image shows ions on an optical lattice.
Credit: SISSA

Davide Mandelli, Andrea Vanossi and Erio Tosatti of the International School for Advanced Studies (SISSA) of Trieste have studied the conditions in which at the nanoscopic level the switch from smooth sliding to stick-slip regime occurs, simulating 'toy-like' systems of 'cold ions'.

"Our studies are based on the research on trapped cold ions. Before we did, such methodology had never been applied to the field of friction", explains Tosatti. "These are experimental studies I call 'toy-like' because they are models employed to explore reality, in the same way as a Lego little house may be used as the model of a real house. We have simulated such systems and used them in our field of research." Tosatti is the coordinator of the research, which appeared in the scientific journal Physical Review. The study, besides SISSA, also involves the Centro Democritos of Officina dei Materiali CNR-IOM.

More in detail…

The three scientists have simulated the sliding of a one-dimensional ion chain of finite length on a substrate generated by laser beams (an optical lattice).

"The lattice forms a periodic sequence of 'barriers' and 'holes', whose depth determines the behavior of the ion chain when advancing on the substrate pulled by an electric field," explains Mandelli, a student at SISSA. When the holes are shallow – technically speaking, when the amplitude of the corrugated potential is small enough – the ion chain can slide in a continuous manner, while when they are deeper the movement of the ions appears more restrained, and thus the stick-slip regime is observed." Another interesting observation" adds Mandelli "regards the role of the chain's inhomogeneity, as a consequence of which some areas get more or less stuck on the substrate. As a consequence, before the sliding process starts, internal 'adjustments' occur in which few ions move in the direction of the pulling force. Also this phenomenon has been observed at macroscopic scales."
In a 2011 study Tosatti e Vanossi had already employed such model to study static friction. With this work they have extended their observations to the field of dynamics.

"Such studies are important for two reasons", explains Mandelli. "On one side, the stick-slip is a complex phenomenon that occurs at every scale whose dynamics are still little-known. Just try to imagine how important it is to understand it from a geological viewpoint, for instance. On the other, with the development of nanotechnologies also from an application point of view it becomes fundamental to know the details of the interaction mechanics of molecules and atoms."

On the connection between mesoscale and nanoscale friction Tosatti and Vanossi have recently published also a "colloquium" (a series of articles in scientific reviews) in the international journal Reviews of Modern Physics. Such research line carried out at SISSA has been recently awarded with a 5-year Advanced Grant by the European Research Council.

http://www.sissa.it/index.php/about/news/1529

Federica Sgorbissa | EurekAlert!
Further information:
http://www.sissa.it

More articles from Physics and Astronomy:

nachricht SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>