For the first time, scientists from the Universities of Sydney and Basel in Switzerland have demonstrated the ability to manipulate and identify a small number of interacting photons (packets of light energy) with high correlation. This unprecedented achievement is an important milestone in the development of quantum technologies. Published today Nature Physics. Stimulated light emission, proposed by Einstein in 1916, is widely observed for large numbers of photons and forms the basis of the invention of the laser. With this research, stimulated emission was now observed for single photons.
Specifically, scientists can directly measure the time delay between a single photon and a pair of related photons scattered in a single quantum dot, such as an artificially created atom.
“This opens the door to manipulating what we might call ‘quantum light’,” said Dr Sahand Mahmoudian, from the University of Sydney’s School of Physics and lead author of the study.
Dr. “This fundamental science paves the way for advances in quantum-enhanced measurement techniques and photonic quantum computing,” said Mahmoudian.
More than a century ago, scientists observing the interaction of light with matter discovered that light is neither a beam of particles nor a wave nature of energy, but exhibits both properties known as wave-particle duality. The way light interacts with matter continues to captivate scientists and the human imagination, both for its theoretical beauty and powerful practical applications.
Whether it’s how light travels through the vast expanses of the interstellar medium or the development of the laser, the study of light is an important science with important practical applications. Without these theoretical foundations, almost all modern technologies would be impossible. No cell phones, no global networks, no computers, no GPS, no modern medical imaging.
One of the advantages of using light in communication – via optical fibers – is that packets of light energy, namely photons, do not easily interact with each other. This allows information to be transmitted at the speed of light with almost no degradation.
But sometimes we want the light to interact. And here everything gets difficult.
For example, light is used to measure small changes in distance using instruments called interferometers. Whether in advanced medical imaging for important but perhaps more mundane tasks such as milk quality control, or in the form of sophisticated instruments such as LIGO, which first measured gravitational waves in 2015, these measurement tools have become commonplace.
Source: Port Altele
