Attotechnology Could Illuminate How Electrons Move
The motion of tiny particles such as electrons is impossible to investigate with current technology. That's because electrons, like other subatomic particles, don't move on the time scale of seconds, but of attoseconds--a billion billionth of a second, or 10-18 seconds.
To put things in perspective (kind of), what a nanosecond (a billionth of a second, or 10-9 seconds) is to a second, an attosecond is to a nanosecond. Due to the challenges in resolving such a tiny pinch of time, the field of "attotechnology" is still very new.
Recently, however, scientists have taken a significant step forward, demonstrating the ability to transmit pulses of light that last for only a single attosecond, using a minimal amount of power. Blink, and you'll miss a few million.
The researchers, led by Dr Fetah Benabid from the University of Bath, have published their results in the journal Science.
One of the most intriguing applications of this degree of light control is what it might teach scientists about the quantum world. On tiny scales, particles don't have definite positions, only probable positions. This unintuitive fact is explained by the dual particle-wave nature of all objects, which has much greater effects for smaller objects.
Being able to illuminate a moving electron with distinct attosecond pulses of light may enable researchers to more accurately measure its movement, and see a little bit more precisely what is going on at that level.
Although this is not the first time that attosecond light pulses have been demonstrated, previous demonstrations required very large amounts of power, making the ability almost useless for commercial and industrial applications due to costs. However, Benabid's group's method requires only one-millionth of the amount of power of previous methods.
The key to the new method is the use of a photonic crystal fiber. The fiber, which is about the width of a human hair, can efficiently trap a broad spectrum of light and an inert gas--the most challenging and expensive part of the set-up. Because light can exist in different modes without strongly interacting, a broad spectrum can be trapped in a single "kagome"-structured fiber. The scientists were able to do this without the use of a photonic bandgap, which marks the first time the physical property--called "bound states within a continuum"--has been experimentally demonstrated.
Hopefully, the ability to efficiently manipulate light will give scientists the tools to probe the sub-atomic world as well as light itself.