Russian and European physicists have come up with a new approach based on the use of “liquid light,” which are entangled particles of light and matter.
This is to perform all types of logical operations used in computers. The press service of the Russian Skoltech Center reported on Friday, July 26, saying that the devices created by scientists perform these operations hundreds of times faster than their electronic counterparts.
“Unlike electrons, photons do not interact with each other, so the invention of a fully optical logic converter has long been a physical and technological challenge. We solved this problem using the unique properties of “liquid light,” which combines the properties of both photons and electrons,” said Denis Sannikov, a researcher at Skoltech University.
Scientists led by Professor Pavlos Lagoudakis of Skoltech have been working for many years on developing various systems that make it possible to control the behavior of so-called “liquid light.” This is a collection of so-called quasiparticles called “exciton-polaritons,” a combination of an electron and a “hole,” a positive charge, as well as an electron and a light particle.
Physicists previously believed that such structures could only exist at temperatures close to zero, but Russian scientists were able to prove several years ago that they can also arise at room temperature. Sannikov and his colleagues created the first polariton transistors capable of operating at room temperature at frequencies hundreds of times higher than their electronic counterparts.
The researchers used these transistors to develop an all-optical device capable of performing the NOR (or-not) logic operation, where a logic gate compares two values to each other and outputs one if both values are zero. Using combinations of multiple NORs, all other logic operations can be performed, allowing for the creation of complex computing systems that rely on them.
To demonstrate the operation of this approach, the scientists created prototypes of NOR gates consisting of multilayer structures made of layers of the polymer MeLPPP, whose molecules interact effectively with light, as well as miniature mirrors made of quartz and thallium oxide. Subsequent experiments with them showed that they are capable of operating at a frequency of about one terahertz, which in the future will make it possible to develop superfast and energy-efficient computers based on “liquid light.”