Synopsis: Phasons Passing By

Simulations help to visualize the propagation of structural excitations, called phasons, that occur in quasicrystals.
Synopsis figure
J. A. Kromer et al., Phys. Rev. Lett. (2012)

Although quasicrystals have long-range order, they lack a unit cell that repeats itself (see 7 October 2011 Focus). In addition to phonon vibrations that occur in regular crystals, quasicrystals exhibit low energy excitations called phasons – propagating patches of rearranged atomic structure. Phasons are of considerable interest because they contribute significantly to the thermal properties of quasicrystals, but the microscopic motion of atoms resulting from a phason propagating through a material hasn’t been clearly seen experimentally.

A model system for understanding phasons is a suspension of colloidal particles, which can be forced into a quasicrystalline order using special arrangements of lasers. Now, in a paper appearing in Physical Review Letters, Justus Kromer at the Berlin Institute of Technology, Germany, and colleagues report simulations that show what phasons should look like in such systems. According to the authors, the relative phases of the laser beams could be appropriately tuned to create a global phasonic drift—a change in potential that ripples through the quasicrystal and forces the particles to rearrange—and they predict the resulting discrete and collective motion of the particles. Kromer et al.’s results could be useful for understanding phasons in real quasicrystalline materials. – Sarma Kancharla


Features

More Features »

Announcements

More Announcements »

Subject Areas

Materials Science

Previous Synopsis

Next Synopsis

Biological Physics

Catapults for Seeds

Read More »

Related Articles

Viewpoint: 3D Imaging of Dislocations
Industrial Physics

Viewpoint: 3D Imaging of Dislocations

A combination of imaging techniques provides an unprecedented 3D view of a network of crystal defects known as dislocations. Read More »

Focus: Quick Changes in Magnetic Materials
Condensed Matter Physics

Focus: Quick Changes in Magnetic Materials

A class of magnetic materials can be reordered at the nanoscale more rapidly than the type usually found in magnetic hard drives, offering a possible route to faster memory devices. Read More »

Synopsis: Why Vapor-Deposited Glasses Are so Stable
Materials Science

Synopsis: Why Vapor-Deposited Glasses Are so Stable

Simulations explain why glasses produced by vapor deposition can be as stable as ordinary glasses that have aged for thousands of years. Read More »

More Articles