In addition to the numerous applications we already know about the so-called “wonder material”, graphene could be used as a frequency multiplier to achieve radiation in the terahertz frequency range, according to new calculations by a German physicist from the University of Augsburg.
According to an article published on nanotechweb.org, new calculations by a German physicist suggest that graphene could function as an inherently strong nonlinear device, or a “frequency multiplier”. This means that the nanomaterial, also known as the “miracle material”, could be used to generate radiation in the terahertz frequency range by irradiating it with more accessible frequencies such as microwaves.
Graphene is a nanomaterial consisting of a two-dimensional layer of carbon just one atom thick, developed in 2004 by Andre Geim and his colleagues at the University of Manchester and the Chernogolovka Institute of Microelectronics Technology in Chernogolovka, Russia.
Graphene is made from graphite, the form of carbon used in pencils, and exhibits some unusual physical properties, including the fact that the material’s electrons behave like relativistic particles, which are massless at rest and move at around 106m/s move. Although that is about 300 times slower than the speed of light in a vacuum, it is still much faster than the speed of electrons in a normal conductor.
The new study by Sergey Mikhailov
Now Sergey Mikhailov from the University of Augsburg has predicted that graphene, when irradiated with electromagnetic waves, emits radiation with a higher-frequency harmonic resonance and can therefore be used as a frequency multiplier. In other words, when the sample is irradiated with a certain frequency of light, it reflects light of a higher frequency.
This “frequency transformation” could be used to generate radiation at frequencies for which no suitable sources exist. For example, it is difficult to generate frequencies above 100 GHz and up to 1-10 THz (1012 Hz, also known as the terahertz gap). In contrast, there are numerous sources of microwave radiation for frequencies below 100 GHz. Scientists could therefore “multiply” microwave frequencies by using a nonlinear device like graphene to generate radiation in the terahertz range, according to Mikhailov in his paper published in the journal Europhysics Letters.
Such terahertz radiation sources could be used in many fields such as security and defense, medicine, astronomy and biological research.
Terahertz radiation penetrates many materials (with the exception of metals) and can therefore eg B. be used at airports to “look through” packages and packages.
“In medicine, it could be used to image cancerous tumors and make an early diagnosis of the disease,” says Mikhailov.
Astronomers are also interested in terahertz radiation because the cosmic microwave background created by the Big Bang contains a terahertz component.
Article from 2006, source: