Minute delay of light in the crystal brought closer the moment of creation of quantum memory

Scientists from the University of Darmstadt (Germany) managed to stop the light for one minute. The light, whose speed almost reaches 300 million meters per second, was completely “frozen” inside the crystal. This phenomenon is called light memory - the process of storing light-transmitted images in crystals. The study brings scientists closer to creating quantum memory, and at the same time helps to go beyond the speed of light, Extremetech writes.

In 1999, scientists slowed the speed of light to 17 meters per second. Two years later, the same group of researchers completely stopped the light, but only for a few fractions of a second. Earlier this year, the Georgia Institute of Technology "froze" the light for 16 seconds. The last record is one minute.

German scientists slowed down the light by the method of electromagnetic-induced transparency (EIT). The experiment began with laser firing of a cryogenically cooled opaque crystal based on yttrium silicate activated by praseodymium. As a result of a complex reaction at the quantum level, the crystal became transparent. Then a second light source was sent to the crystal, followed by turning off the first (control laser), which took away the ability to transmit light from the crystal. The light was trapped because it could no longer be reflected. The light literally stopped.

The photon energy was transferred to the atoms inside the crystal; the photon information was converted into atomic spin excitations. After the control laser was turned on, spin excitations released photons. Atomic spins (angular momenta) were able to maintain data integrity for almost a minute, after which the light impulse (image) was destroyed. In essence, the technology makes it possible to store and retrieve data from light quantum memory.

You can also increase the data storage period by using other crystals, such as yttrium silicate with the addition of europium, and special magnetic fields. The experiment is one of the first steps towards creating a long-range quantum network. Quantum Internet will appear as soon as a way to coherently store light at room temperature is found.

A high-level programming language for quantum computing, which will determine the future of computers, has already been created.

The article is based on materials https://hi-news.ru/research-development/minutnaya-zaderzhka-sveta-v-kristalle-priblizila-moment-sozdaniya-kvantovoj-pamyati.html.