Synopsis: Flexing Some Graphene Muscle

Two groups propose coupling light into graphene surface plasmons by mechanically rippling the sheet of carbon atoms.
Synopsis figure
J. Schiefele et al., Phys. Rev. Lett. (2013)

Among its many talents, the two-dimensional carbon structure of graphene can sustain surface plasmons—collective electronic oscillations—from midinfrared to terahertz frequencies. Plasmons in this frequency range could be the basis of nanometer-size devices that join electronic functions with optics. However, getting light in and out of graphene plasmons is a tall order: it requires patterning the material with periodic structures to couple photons to the electronic oscillation. Not only does physical patterning prevent tunability, but it also causes energy loss due to scattering off the imposed structure. In Physical Review Letters, two independent research groups propose that inducing vibrations in graphene to create the necessary periodic grating could be a more efficient way to convert photons to plasmons.

In one report, Mohamed Farhat at the King Abdullah University of Science and Technology (KAUST), Saudi Arabia, and his colleagues consider a sheet of graphene nudged at one side by a mechanical actuator. This generates flexural waves on the graphene sheet, which establish the grating pattern required to have energy flow from incident light into surface plasmons. By matching the wave number of the incident field with that of the plasmon, the coupling can be markedly enhanced. By their calculations, one could couple 50% of the light energy, as opposed to 2% for unmodulated graphene.

In the other report, Jürgen Schiefele, at the Complutense University of Madrid, Spain, and colleagues propose placing the graphene sheet on a piezoelectric substrate. Electrically induced mechanical vibrations set up the graphene modulation that matches the photon and plasmon phases. If developed practically, such devices could be useful in highly sensitive chemical detection, conversion of light to electricity, and nano-optoelectronics. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Graphene

Previous Synopsis

Particles and Fields

Particle Masses Don’t Budge

Read More »

Next Synopsis

Related Articles

Synopsis: Graphene Helps Catch Light Quanta
Graphene

Synopsis: Graphene Helps Catch Light Quanta

The use of graphene in a single-photon detector makes it dramatically more sensitive to low-frequency light. Read More »

Focus: Graphene Sliding on Graphene
Mechanics

Focus: Graphene Sliding on Graphene

Creating a bulge in a graphene sheet offers the first measurement of the shear forces between graphene layers, an essential factor in many graphene-based devices. Read More »

Synopsis: Crumpled Graphene
Graphene

Synopsis: Crumpled Graphene

The crumpling of graphene sheets explains a “soft spot” in the material’s mechanical response. Read More »

More Articles