The researchers managed to stop a light beam for a fraction of a second * an important step towards quantum computing and quantum encryption
Physicists claim that they brought a beam of light to a complete stop for example a second particle and then let it continue on its way.. A team from Harvard University stopped the pulse of light without taking all of its energy from it. This was reported by the journal Nature. Controlling the speed of light particles, known as photons, to store and process data could lead to the development of quantum computers.
In an experiment conducted in 2001, pulses of light were stored for a short time when light particles were captured by atoms in a gas. In the Harvard experiment this was achieved by stopping the light and its energy in a kind of freeze.
Light normally travels at 299,792 kilometers per second, but it slows down when it passes through some materials such as glass. The team shot a pulse-shaped beam of light through a sealed glass cylinder containing a gas containing atoms of the element rubidium, illuminated by a strong radiation of light known as control radiation. As the pulse traveled through the rubidium gas, the researchers turned off the control beam, creating a holographic print of the pulse signal on the rubidium atoms.
Earlier experimental approaches then switched to a single control beam to recreate the signal pulse, which then continued on its way. Anyway, in this study, the researchers worked on two control pulses that created an interference pattern that behaves like a stack of mirrors. As the regenerated pulse tries to continue its path inside the glass cylinder, the photons move back and forth, but the pulse as a whole remains stable. The light beam actually froze. The researchers were able to keep the photons trapped in this way for 10-20 microseconds.
The research was carried out by Mikhail Lukin, Michal Bajcsy and Alexander Zibrov from the Department of Physics at Harvard University, in Cambridge, Massachusetts.
quantum leap
Bigxy says that remote applications of light control could form the basis of quantum computers. "In quantum computers, the data can be transferred from photon to photon to photon. And in order to allow photons to communicate with each other, you need to control the process very carefully." said.
Prof. Suhail Zubairy, a physicist at Texas A&M University, says that the Harvard team's achievement was a significant step towards the emergence of quantum computing and quantum encryption. Quantum encryption may provide a secure form of electronic encryption, because the process of eavesdropping on an electronic message will cause errors in the copied message and obfuscate it. This will make it possible to exchange keys on a public channel, which is impossible to do in the classic systems that can be deciphered through wiretapping. With quantum encryption, you can always tell if someone else is looking at your message," said Prof. Zubieri.
For news at the BBC
