Scientists have managed to stop the light for one minute.
Researchers from the University of Darmstadt (Germany) managed to stop the flow of light for one minute. Light, as the fastest matter known in the universe (speed 300.000 km / s) was stopped inside the crystal. Thus, it is possible to create a so-called light memory , when information carried by the light is accumulated by the crystal. Apart from the fact that such a study in itself excites the imagination, it can, with very great success, become the background to the creation of long-range quantum networks, and maybe this study will give hints on how to make the speed of light more than the value limited by the universe. .
If we turn to history, then in 1999, scientists managed to reduce the speed of light to 17 m / s, and then, two years later, the same group of researchers completely stopped the light, but only by a few fractions of a second. Earlier this year, researchers from the Georgia Institute of Technology (USA) managed to stop the light for 16 seconds, and now scientists from Darmstadt have increased this threshold by a minute.
')
To stop the light, scientists used the so-called electromagnetically induced transparency (EIT) technique. They used a cryogenically cooled, completely opaque crystal of an alloy of yttrium silicate and praseodymium. The controlled laser beam is directed into the crystal, and thus creates a complex reaction at the quantum level, making the crystal completely transparent. The second light source (data / image source) is then directed to a fully transparent crystal. Then, the controlled laser turns off, returning the crystal to full opacity. This action not only allows us to enter into the light that carries the data into the crystal trap, but also allows us to eliminate its reflection due to opacity. Thus, the light is stopped.
Due to the lack of freedom of movement, the energy of the photons is collected by the atoms of the crystal and the data carried by the light are converted into atomic spins (not to be confused with the human back). In order to release the light from the crystal, they re-enable the controlled laser, which makes the crystal again transparent and atomic spins are released on photons. These atomic spins can maintain coherence (data integrity) for a minute, after which the light beam disappears. In essence, the creation of such conditions allows for the storage and retrieval of data from the light memory.
In the image above, you can see how the scientists successfully saved a simple image (three horizontal lines) in the crystal for 60 seconds. It is possible to store data in the crystal for a longer period of time in the case of using other chemical elements, such as europium doped with yttrium silicate and using specially created magnetic fields.
A light memory that provides quantum coherence (such as polarization and quantum entanglement) is vital to the creation of long-range quantum networks. Also, as is the case with conventional electronic routers, quantum routers must be able to store incoming packets and then forward them — something that allows such a discovery. Moreover, there are several barriers to overcome, before turning to quantum Internet, for example, it is necessary to find a way to coherently store light, accompanied by such a small amount of noise that single photons could be safely stored / received and all this must be done in room temperature conditions. Cryogenics, is quite applicable in the conditions of some data processing center, but it is very difficult to imagine a cryogenically cooled router at home :)
If we turn to history, then in 1999, scientists managed to reduce the speed of light to 17 m / s, and then, two years later, the same group of researchers completely stopped the light, but only by a few fractions of a second. Earlier this year, researchers from the Georgia Institute of Technology (USA) managed to stop the light for 16 seconds, and now scientists from Darmstadt have increased this threshold by a minute.
')
To stop the light, scientists used the so-called electromagnetically induced transparency (EIT) technique. They used a cryogenically cooled, completely opaque crystal of an alloy of yttrium silicate and praseodymium. The controlled laser beam is directed into the crystal, and thus creates a complex reaction at the quantum level, making the crystal completely transparent. The second light source (data / image source) is then directed to a fully transparent crystal. Then, the controlled laser turns off, returning the crystal to full opacity. This action not only allows us to enter into the light that carries the data into the crystal trap, but also allows us to eliminate its reflection due to opacity. Thus, the light is stopped.
Due to the lack of freedom of movement, the energy of the photons is collected by the atoms of the crystal and the data carried by the light are converted into atomic spins (not to be confused with the human back). In order to release the light from the crystal, they re-enable the controlled laser, which makes the crystal again transparent and atomic spins are released on photons. These atomic spins can maintain coherence (data integrity) for a minute, after which the light beam disappears. In essence, the creation of such conditions allows for the storage and retrieval of data from the light memory.
In the image above, you can see how the scientists successfully saved a simple image (three horizontal lines) in the crystal for 60 seconds. It is possible to store data in the crystal for a longer period of time in the case of using other chemical elements, such as europium doped with yttrium silicate and using specially created magnetic fields.
A light memory that provides quantum coherence (such as polarization and quantum entanglement) is vital to the creation of long-range quantum networks. Also, as is the case with conventional electronic routers, quantum routers must be able to store incoming packets and then forward them — something that allows such a discovery. Moreover, there are several barriers to overcome, before turning to quantum Internet, for example, it is necessary to find a way to coherently store light, accompanied by such a small amount of noise that single photons could be safely stored / received and all this must be done in room temperature conditions. Cryogenics, is quite applicable in the conditions of some data processing center, but it is very difficult to imagine a cryogenically cooled router at home :)
Source: https://habr.com/ru/post/188020/
All Articles