This may have practical significance in the control of nanoscale friction. The results have been published in the scientific journal Nature Materials.
An oscillating Atomic Force Microscope tip in proximity to the Charge Density Wave (CDW) on NbSe2 surface. The yellow and blue spheres are the Selenium and Niobium atoms forming the lattice.
University of Basel
Friction is often seen as an adverse phenomenon that leads to wear and causes energy loss. Conversely, however, too little friction can be a disadvantage as well – for example, running on an icy surface or driving on a wet road.
An understanding of frictional effects is therefore of great importance – particularly in the field of nanotechnology, where friction has to be controlled at a nanoscale. A recent study conducted by researchers from the University of Basel, the University of Warwick, the CNR Institute SPIN in Genoa and the International Centre for Theoretical Physics (ICTP) in Trieste has helped to give a better understanding of how friction works in microscopic dimensions.
In the experiment led by Prof. Dr. Ernst Meyer, Professor of Experimental Physics at the University of Basel, the team vibrated the nanometer-sized tip of an atomic force microscope above the surface of a layered structure of niobium and selenium atoms. They selected this combination due to its unique electronic properties, and in particular the charge-density waves formed at extremely low temperatures. The electrons are no longer evenly distributed as in a metal, but instead form areas where the electron density fluctuates between a high and low range.
Energy losses in the vicinity of charge density waves
The researchers registered very high energy losses in the vicinity of these charge density waves between the surface and the tip of the atomic force microscope, even at relatively large distances of several atomic diameters. “The energy drop was so great, it was as if the tip had suddenly been caught in a viscous fluid,” says Meyer.
The team observed this energy loss only at temperatures below 70° Kelvin (-203° C). Since charge density waves do not occur at higher temperatures, it interpreted this as evidence that frictional forces between the probe tip and charge density waves are the cause of the energy loss.
The theoretical model shows that the high energy loss results from a series of local phase shifts in the charge density waves. This newly discovered phenomenon may be of practical significance in the field of nanotechnology, particularly as the frictional effect can be modulated as a function of distance and voltage.Original citation
Nature Materials, published online XXX | doi: 10.1038/NMAT3836Further information
Olivia Poisson | Universität Basel
Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center
Supermassive black hole model predicts characteristic light signals at cusp of collision
15.02.2018 | Rochester Institute of Technology
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy