The function of transistors stems from the controlled motion of electrons. This method has been used for decades, but it still has some drawbacks. First, electronic devices tend to get hot while performing tasks, which means that some of the energy is converted into heat that is wasted instead of being used for actual work. To prevent heating, the equipment is equipped with cooling elements, thus wasting more energy. Second, the processing speed of electronic devices is limited. Some of these problems can be solved by using photons instead of electrons. Devices that encode information using photons generate less heat, use less energy and work faster.
So scientists all over the world are doing research in the field of optical computers. But the main problem is that unlike electrons, photons do not interact. So the researchers came up with a way to "train" photon interactions. One idea is to couple photons with other particles. A team of researchers from ITMO's department of physics and engineering has demonstrated a new implementation in which photons are coupled to excitons in a monolayer semiconductor. When electrons are excited, excitons form in the semiconductor, leaving holes. Both electrons and their holes can interact to produce a new particle, an exciton.
"If we strongly coupled excitons to light particles, we would get polarons, which means they can be used to transmit information very quickly, and at the same time, they can interact with each other very well," explained Vasily Kravtsov, lead researcher at ITMO university and one of the paper's authors.
Creating transistors based on polarons is not easy. The researchers need to design systems in which the particles can persist long enough while still maintaining their high interaction intensity.