20 Mar '19
Researchers at MIPT, a leading Moscow-based technology university also known as Phystech, partnered with Andre Geim, a Nobel Prize winner and Russian expat working in the UK, to develop a compact graphene-based terahertz wave detector which is tiny enough to fit into a mobile phone or computer chip.
Terahertz (THz) radiation has been in the limelight across disciplines such as optics, microelectronics and other high tech fields. The radiation’s most well-known property as of today is its theoretical ability to make the inside of objects visible. Such waves could one day help revolutionize ultrahigh speed data transfer, real-time observation of the way living cells work, and a wide range of other applications.
The opportunity has received much attention across global academia. However, progress has been hindered so far by the hugeness of modern THz detectors and problems researchers have faced using plasmon resonators (sets of microscopic pieces of metal, silicon or other substances which cover the surface of another material).
A group led by Georgy Fedorov at MIPT appears to have bypassed the current snags by using graphene. It’s exactly the creation of this new 2D carbon material that brought Andre Geim and his colleague Konstantin Novoselov the 2010 Nobel Prize in Physics. It was found that electrons inside graphene can move at record high velocities, finding basically no obstacles on their way to collide into. That has prompted the Moscow-based scientists to think that the material can be used as base for THz resonators.
The idea is reported to have been successfully implemented when the team coupled a terahertz wave capturing antenna to a transistor designed as a “sandwich” comprising two boron nitride films and a double graphene layer “packed” between the films. Electron oscillations that occur inside the resonator impact the way electricity traverses the transistor. The MIPT team and Mr. Geim have proved that in the process, not only can THz radiation become visible, but also a required part of its spectrum can be tuned to.