Engineers have developed a nanoscale device that works 10 times faster than the best modern transistors and generates powerful terahertz waves.
The terahertz frequency spectrum is located on the border between microwave and infrared radiation, fluctuating in the range of 3·1011-3·1012 Hz. Such waves are safe for humans, but they can penetrate clothing, walls and trees, as well as transmit large amounts of data, which in the future can improve wireless communication. So far, THz waves are rarely used due to the complexity and high cost of their generation..
Researchers at the École Polytechnique de lausanne have developed an inexpensive all-electric nanodevice that can instantly generate intense terahertz waves from a tiny source. In the process, it generates a powerful «spark», with a voltage jump from 10 V to 100 V, in the picosecond range. Every second the system is capable of produce up to 50 million signals, and when connected to an antenna emit powerful THz waves.
The device consists of two metal plates spaced less than 20 nm apart. When a voltage is applied, electrons are directed to one of the plates, forming a nanoplasma. Once the voltage reaches a certain threshold, particles almost instantly move into the second plate. This rapid jump creates an intense pulse that produces high frequency waves..
According to scientists, this technology could revolutionize security systems, wireless communications, medical imaging, and sensing. The compact size of the devices will allow in the future to place them even on smartphones microcircuits and flexible wearable electronics.
Earlier, we also reported on the invention of a generator that produces electricity from the air..
A nanoscale device that can see through walls
text: Ilya Bauer, photos and videos: EPFL