Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Electronics: Graphene sheets’ growing attractions

A theoretical and numerical study of graphene sheets reveals a property that may lead to novel opto-electric devices and circuits

One-atom-thick sheets of carbon — known as graphene — have a range of electronic properties that scientists are investigating for potential use in novel devices.

Plasmon energy states in an array of four graphene sheets. Each plane represents different plasmon energy states resulting from different numbers of electrons in each sheet.

Copyright : 2012 A*STAR Institute of Materials Research and Engineering

Graphene’s optical properties are also garnering attention, which may increase further as a result of research from the A*STAR Institute of Materials Research and Engineering (IMRE). Bing Wang of the IMRE and his co-workers have demonstrated that the interactions of single graphene sheets in certain arrays allow efficient control of light at the nanoscale1.

Light squeezed between single graphene sheets can propagate more efficiently than along a single sheet. Wang notes this could have important applications in optical-nanofocusing and in superlens imaging of nanoscale objects.
In conventional optical instruments, light can be controlled only by structures that are about the same scale as its wavelength, which for optical light is much greater than the thickness of graphene. By utilizing surface plasmons, which are collective movements of electrons at the surface of electrical conductors such as graphene, scientists can focus light to the size of only a few nanometers.

Wang and his co-workers calculated the theoretical propagation of surface plasmons in structures consisting of single-atomic sheets of graphene, separated by an insulating material. For small separations of around 20 nanometers, they found that the surface plasmons in the graphene sheets interacted such that they became ‘coupled’ (see image). This theoretical coupling was very strong, unlike that found in other materials, and greatly influenced the propagation of light between the graphene sheets.

The researchers found, for instance, that optical losses were reduced, so light could propagate for longer distances. In addition, under a particular incoming angle for the light, the study predicted that the refraction of the incoming beam would go in the direction opposite to what is normally observed. Such an unusual negative refraction can lead to remarkable effects such as superlensing, which allows imaging with almost limitless resolution.

As graphene is a semiconductor and not a metal, it offers many more possibilities than most other plasmonic devices, comments the IMRE’s Jing Hua Teng, who led the research. “These graphene sheet arrays may lead to dynamically controllable devices, thanks to the easier tuning of graphene’s properties through external stimuli such as electrical voltages.” Graphene also allows for an efficient coupling of the plasmons to other objects nearby, such as molecules that are adsorbed on its surface. Teng therefore says that the next step is to further explore the interesting physics in graphene array structures and look into their immediate applications.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

Journal information

Wang, B., Zhang, X., García-Vidal, F. J., Yuan, X. & Teng, J. Strong coupling of surface plasmon polaritons in monolayer graphene sheet arrays. Physical Review Letters 109, 073901 (2012).

A*STAR Research | Research asia research news
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>