Scientists at the Massachusetts Institute of Technology (MIT) and Harvard University have recently surpassed one of the major obstacles blocking the path to developing advanced quantum computers.
The joint team was able to develop a method of converting a laser beam into a stream of single photons. Their approach is significant because it also blocks undesired particles from getting through.
Quantum computers are heralded as very advanced machines, capable of conducting calculations so complex that they would put even the most advanced supercomputers available today to shame.
However, efforts to produce such devices in real life have thus far fallen short, due to a large number of technical challenges that have yet to be overcome. The recent achievement is a major step forward.
In addition to opening the way for the creation of a new generation of computers, the study could also enable advancements in quantum-based communications, which are thought to be invulnerable to interception and decryption.
The team published details of its tremendous achievement in this week's issue of the top scientific journal Nature. The leader of the research group was MIT PhD student Thibault Peyronel.
The MIT Lester Wolfe professor of physics, Vladan Vuletić, believes that the study could set the stage for the creation of devices such as quantum gates. These would enable a single photon to switch the polarization or direction of travel of another photon.
Vuletić, also the senior author of the Nature paper, says that this ability is very important because photons – the basic particles that make up light – interact weakly with each other in nature.
With the new system, researchers explain, only one photon passes through a cloud of atoms, regardless of how many are sent through. Basically, what this cloud does is order the chaotic travel patterns of photons into a single file.
“I view this work as a true breakthrough in quantum optics, as the authors realize a completely novel way of inducing strong interactions between single photons,” comments ETH Zürich professor of physics Atac Imamoglu, who was not part of the research team.