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


Announcements

More Announcements »

Subject Areas

Materials Science

Previous Synopsis

Next Synopsis

Biological Physics

Catapults for Seeds

Read More »

Related Articles

Focus: New Form of Carbon Stores Lots of Gas
Graphene

Focus: New Form of Carbon Stores Lots of Gas

Carbon honeycomb, a new carbon structure, could store large amounts of hydrogen gas, which may benefit fuel cell technology. Read More »

Synopsis: Trees Crumbling in the Wind
Materials Science

Synopsis: Trees Crumbling in the Wind

Lab experiments with wooden rods help explain why all trees—irrespective of size or species—break when battered by wind blowing at the same critical speed. Read More »

Synopsis: Growing Crystals in Macrosteps
Materials Science

Synopsis: Growing Crystals in Macrosteps

Simulations describe how crystals are able to grow past impurities by forming multilayer steps. Read More »

More Articles