Quantum photography technology

Recently, the team of Academician Guo Guangcan of the Chinese University of Science and Technology made an important breakthrough in the field of optical quantum storage, increasing the storage time of coherent light to 1 hour, greatly refreshing the German team's world record of optical storage 1 minute, and taking an important step towards the realization of quantum U disk. This achievement was recently published in the international academic journal Nature? The newsletter has been published.

Photons don't stay in one place as easily as electrons and ions. According to Einstein's theory of relativity, light is always in motion. But in optical quantum computing, optical quantum communication or other places (quantum photography, quantum U disk), sometimes we want some photons to stop and wait. What do we do? One idea is to let atoms absorb photons and leave them as they are after a period of time. Vomiting Come out. To realize this process, we must first have an atomic frequency comb (AFC). Simply speaking, it is a material, and the transmission spectrum is a comb function. So the spectrum of emergent light is equal to the spectrum of incident light multiplied by a comb function-"emergent light is equal to the convolution of incident light and comb function-"emergent light is equal to the periodic extension of incident light, which is also called photon echo, because it is just like echo? UH huh? As long as the time between two signals is controlled, storage can be realized.

One of the characteristics of modern quantum computers is that they have no memory and can't store optical data, just like computers don't have hard disks, so their data are either encoded and decoded by other data, and electrical signals become optical signals (Chapter 9), or optical fibers are directly connected (7500 axiomatic optical fiber network) or laser communication (Mozi satellite), so quantum computers can't handle relatively large data. With a USB flash drive, it means that they can handle more data and appear.

It is very difficult to invent special materials to slow down the propagation speed of light, and to ensure that the basic characteristics of light or the change of information is very small. The success of this technology will certainly bring more optical applications, especially the development and application of optical transmission and storage materials. It is impossible to keep light. It is the direction to keep light energy or optical information in a certain space for a longer time. This project has a bright future, especially in the development of optical materials.