Graphene, an ordered monolayer of carbon, is the thinnest substance known, and yet has extraordinary mechanical strength. A new study shows that its two-dimensional network of atoms can even trap light.
Thin, thinner, graphene. Graphene, a monolayer of carbon in which the atoms are arranged in a two-dimensional honeycomb network, is the thinnest net in the world, is highly stable. Andre Geim and Konstantin Novoselov received the Nobel Prize for Physics in 2010 for their discovery of the electrical conductivity of graphene. Indeed, graphene could in future replace silicon as the basis for extremely small and extremely fast transistors, and is therefore the subject of intense research.
The high mobility of electrons in graphene arises from the fact that they are confined to the hexagonal lattice. An international team led by the American physicist Dimitri Basov has now shown that photons too can be trapped within the lattice and move freely along it. "It is even possible to control the light waves within the lattice," says physicist Dr. Fritz Keilmann, who is affiliated with Ludwig-Maximilians-Universitaet (LMU) in Munich, the Center for Nanoscience (CeNS) and the Max Planck Institute for Quantum Optics (MPQ), and contributed significantly to the new work.
Computers with optical switches
Such control can be exerted using electric fields and currents. Hence, in future, the behavior of light in graphene could be tuned electrically, and the converse may also be feasible. Since the light is confined to nanocables with dimensions of a millionth of a millimeter, switching times could be reduced to less than a picosecond (0.000000000001 sec). "It might even be possible to develop computers whose graphene transistors could be switched both optically and electrically," says Keilmann.
Theoretical calculations had previously suggested that photons, specifically long-wavelength infrared photons, could indeed be propagated along
|Contact: Luise Dirscherl|