Researchers from Delft technical University have developed a new mechanical quantum memory with a long retention time, high efficiency of reading and the ability to operate at telecommunication wavelengths. An article about the development published in the journal Nature Physics.
To create large quantum networks researchers must first develop efficient quantum repeaters. A key component of these repeaters are quantum memory devices, which are analogues of computer devices such as random access memory (RAM). Ideally, the quantum memory must be able to store information for a long time, store the true quantum state, to read the data effectively and to work at low frequencies telecommunication waves. Although physicists have made great progress in the development of quantum memory, none of the proposed solutions are unable to meet all these requirements simultaneously.
“We have developed a system that can store the information a few milliseconds, based on our previous work. Then we tested it and found that the retention time of approximately two milliseconds. says one of the researchers, Professor Delft University of technology Simon Groeblacher In a second step, we had to check whether it exists in the quantum state after this time. To do this, we created a superposition of the mechanical system and considered as a phase in a superposition will change with time”.
When the researchers first estimated they created quantum memory, we found that her state of superposition decays faster than the total lifetime of the system. This was not surprising, because similar behavior has been observed previously for the same systems. Then physics decided to continue with this system to better understand the mechanisms explaining such a short time decoherence.
New memory researchers has several important advantages. The most important thing is that it is fully machinable. This means that the optical wavelengths at which working memory can be selected, because the optical and mechanical resonances of the system is completely artificial. Researchers have developed them using the computer, and then made the device pattern.
A previously developed quantum storage device has reached promising results, but almost nobody managed to get them to work at the Telecom wavelengths (about 1550 nanometers), is designed to transmit information over long distancesI. Moreover, until now, the device is able to operate at these wavelengths, was either very difficult or could not maintain the state of the system long enough.
The goal of future studies physics to better understand why the destruction of the quantum state occurs faster than its life time, and to mitigate this effect. The researchers plan to improve the performance of their quantum memory, to facilitate implementation of devices based on it. Moreover, scientists proposed optical scheme would give impetus to the development of other components of the quantum memory. The ultimate goal of researchers is in the implementation they created quantum memory in large quantum network.