by Jeff Roberts
Scientists at EPFL have succeeded in capturing the first-ever snapshot of light behaving as a particle and a wave,Phys.org reports.
Back when Einstein first popularized the idea that light actually behaves as both a particle and wave, scientists began the mighty endeavour of capturing this concept visually.
However, this is no easy task – the closest we have come is seeing either wave or particle, but always at different times.
But EPFL scientists have now come up with a clever way to counteract this issue.
The experiment is set up like this:
A pulse of laser light is fired at a tiny metallic nanowire. The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels along this tiny wire in two possible directions, like cars on a highway. When waves travelling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment, radiating around the nanowire.
As the electrons interacted with the confined light on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone’s team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light.
As mentioned above, this affects their speed, making them move faster or slower. This change in speed appears as an exchange of energy “packets” (quanta) between electrons and photons. The very occurrence of these energy packets shows that the light on the nanowire behaves as a particle.
“This experiment demonstrates that, for the first time ever, we can film quantum mechanics – and its paradoxical nature – directly,” says Fabrizio Carbone. In addition, the importance of this pioneering work can extend beyond fundamental science and to future technologies. As Carbone explains: “Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing.”
Source: Collective Evolution