Research
www.kaust.edu.sa
KAUST Researchers Advance Field of Graphene Plasmonics
December 2013
7
light, although it is atomically thin. These features have fueled research all around the world to investigate graphene’s potential applications in many areas.” Dr. Farhat, Dr. Hakan Bagci, KAUST Assistant Professor of Electrical Engineering, and Dr. Sebastien Guenneau, a senior researcher from Institut Fresnel at Aix-Marseille Université (France), are examining the use of graphene in photonics and optics. In a paper recently published in Physical Review Letters, which was also selected as the journal editors’ suggestion (http://prl.aps.org/abstract/PRL/v111/i23/e237404), Dr. Farhat, Prof. Bagci, and Prof. Guenneau propose a novel solution to the challenging problem of exciting surface plasmons on graphene using electromagnetic fields at a broad band of frequencies. Plasmons are quasiparticles that are produced from the quantization of plasma oscillation. “Using the interplay of sound and light, we succeeded in efficiently exciting graphene plasmons. This process otherwise requires complicated and rigid setups,” states Dr. Farhat. “Our design, however, offers enhanced reconfigurability and an easier way for building novel photonic devices.” Dr. Farhat and the team studied plasmonic field interactions on graphene at nano-scales. “This process leads to the generation of surface plasmons on graphene’s surface,” he explains. As a result of collective oscillations of conduction electrons at the interface between the metals and dielectrics, metallic surface plasmons are generated. These have many “interesting features,” notes Dr. Farhat, but the most important feature is that they allow for the subwavelength manipulation of light. It was surprising to the researchers that, through corrugating the layer of graphene through flexural waves,
Prof. Hakan Bagci (L) and postdoctoral fellow Dr. Mohamed Farhat (R) discuss their work on graphene plasmonics in Prof. Bagci’s office at KAUST.
it was possible to absorb half the incident energy, despite the fact that the thickness of graphene is around 0.3 nm. “Plasmonic devices usually have thicknesses in the order of the micrometer,” notes Dr. Farhat. “This finding is very important as it shows it is possible to manipulate and harvest light using very thin structures. One potential application of this concept is the design of thinner and lighter photovoltaic cells that absorb sunlight in a broad band of frequencies.”
“Graphene is the material of the 21st century, and it offers tremendous possibilities to revolutionize
The team’s findings have broadened the level of knowledge in the emerging field of acoustical-optics in
people’s lives,” explains Dr. Mohamed Farhat, a KAUST postdoctoral fellow in the Computational
graphene. “This field has so far been remarkably under-studied,” Dr. Farhat says. “Our research work could
Electromagnetics Laboratory. “Over the last few years, it has been shown that a sheet of graphene
be a significant step towards the integration of graphene plasmonics into realistic and multiple applications,
conducts electricity better than silver; it is harder than diamond; and it absorbs 2.3% of the incident
prompting further advances in the emerging field of transformational plasmonics.”
Raja Swaidan Wins Award at the International Membrane Science and Technology Conference Swaidan’s presentation was entitled, “Intrinsically UltraMicroporous Polyimide Sieves for Gas Separation.”
The
presentation outlined a new strategy for the development of more robust and practical gas separation materials. The work encourages a departure from current efforts towards highly permeable materials, emphasizing the importance of selectivity in membrane-based gas separation applications. The talk discussed the economics favoring such an approach and successes by Prof. Pinnau’s team in the design, synthesis, and characterization of target materials. Swaidan, a US citizen of Jordanian descent, is a founding student of KAUST and was involved in helping design and set up the gas permeation systems in AMPM with two other founding students under the guidance of Dr. Eric Litwiller, a senior research scientist. “Under Eric’s leadership, I acquired an invaluable set of skills that
Raja Swaiden, third from left, is congratulated by Dr. Bader Ghanem, Dr. Eric Litwiller, Professor Ingo Pinnau, and Dr. Xiaohua Ma.
supplement my knowledge from the classroom,” says Swaidan. “Now we have full control over state-of-the-art equipment that gives us insightful data only few have access to worldwide.”
Raja Swaidan, a PhD candidate in Chemical Engineering in the
Australia, on Nov. 26. He received a certificate and cash prize.
Swaidan was not the only KAUST presenter at the conference;
Advanced Membrane and Porous Materials Center (AMPM), won
Swaidan is supervised by Professor Ingo Pinnau, Director of the
he shares that his talk and those of two other colleagues from
the International Membrane Science and Technology Conference
AMPM Research Center, and Dr. Bader Ghanem, lead scientist in
AMPM sparked a lot of interest in KAUST and respect for the work
(IMSTEC) 2013 Best Oral Student Presentation Award in Melbourne,
Prof. Pinnau’s high-performance polymer synthesis group.
being done in AMPM.
Souraya Goumri-Said Named Associate Editor of Frontiers Physics Journal Souraya Goumri-Said, a postdoctoral fellow working with Prof. Sahraoui
to peer-review. Frontiers has recently partnered with the Nature Publishing
Chaeib in the Nano-Biophysics Laboratory in the Physical Science and
Group to advance the global open science movement.
Engineering (PSE) Division, has been named as an associate editor in the
At KAUST, Goumri-Said’s main area of research is density functional
interdisciplinary section of Frontiers’ physics journal. As such, she will
theory applied to material science and the modeling of the physical properties
be responsible for building the review editorial board and overseeing the
of functionalized materials, such as spintronics, ceramics, carbides, nitrides,
review process.
and materials for storage hydrogen. She also specializes in modeling optical
Frontiers is a Swiss, Gold open-access academic publisher launched in Souraya Goumri-Said
photonic devices and nanostructures for photovoltaic applications.
2007 as a grassroots initiative by scientists of the Swiss Federal Institute of
Goumri-Said is also associate editor of the Central European Journal of
Technology (EPFL). It is the first publisher to develop its own customized
Physics within the Springer Verlag Edition since 2008. She is the author of
IT platform to facilitate open-access publishing and offer novel solutions
more than 53 papers.