A team of physicists from Germany successfully transported light stored in the quantum memory of ultra-cold Rubidium-87 atoms to a distance of 1.2 mm. They demonstrated that this controlled process and its dynamics have only a small effect on the properties of light.
Controlled control and storage of quantum information, as well as the ability to obtain it are the most important prerequisites for progress in quantum communication and computing. Optical quantum memory, which allows you to memorize and read quantum information stored in light, can become the basis for the technology of quantum repeaters or tools for linear quantum computing.
In recent years, scientists have proven that groups of atoms are perfectly suited to store and retrieve optical quantum information. With the technology of electromagnetic-induced transparency, light pulses can be captured and coherently displayed to create a collective excitation of atoms. Since this process is mostly reversible, light can be released again with high efficiency, writes Phys.org.
In their work, scientists from the University of Mainz described a controlled movement of such stored light at a distance of 1.2 mm, that is, more storage medium. In the past, they have already developed a method for assembling cold atoms to move on an “optical conveyor”, using two laser beams. The advantage of this method is that it allows to move a relatively large number of atoms and place them with high accuracy without significant loss and unwanted heating.
Now physicists have managed to apply this technique to move clouds consisting of cooled rubidium-87 atoms that act as “light memory”.
“We kept the light, so to speak, by putting it in a suitcase, only in our case the suitcase is made of a cloud of cold atoms,” explained Professor Patrick Windessinger. – We moved the suitcase a short distance and then removed the light from it. This is very interesting not only in terms of physics, but also for quantum communication, because light is not so easy to catch and if you want to transport it somewhere, it is usually lost in the process.