For some time now, the electronics industry has been striving to develop components for switching frequencies in the terahertz range. Graphene, which has a high electrical conductivity and is compatible with all existing electronic technologies, is regarded as a promising material and potential successor to silicon. In particular, it has long been theoretically predicted that graphene could be a very efficient "nonlinear" electronic material, i.e. a material that can convert an applied alternating electromagnetic field into fields of much higher frequency. However, all experimental efforts over the last ten years to prove this effect in graphene have been unsuccessful.
Now scientists have demonstrated that frequencies can be transposed from the GHz to the THz range - and even with high energetic efficiency. The researchers demonstrated this effect by means of a graphene monolayer, explains Michael Gensch, whose research group is investigating ultra-short time physics at the Helmholtz Centre HZDR in Dresden. And not only that: Their cooperation partners around profesor Dmitry Turchinovich, experimental physicist at the University of Duisburg-Essen (UDE), have succeeded in describing the measurements quantitatively with the help of a simple model based on basic physical principles of thermodynamics.