Have you ever wondered why your computer and other electronic devices sometimes run fast and sometimes slow? It all boils down to the rate at which electrons, the tiniest particles in our microcosm, flow out of tiny wires inside the transistors of electronic chips and form pulses. Developing methods to increase this speed is critical to achieving the maximum performance potential of electronics and its applications.

But what is the shortest possible time for electrons to flow out of a small metallic lead in an electronic circuit?

Using extremely short laser flashes, a research team led by Professor Eleftherios Gulielmakis, Head of the Extreme Photonics Group at the Institute of Physics at the University of Rostock, and colleagues at the Max Planck Institute for Solid-State Research in Stuttgart, has developed state-of-the-art technology to extract electrons from a tungsten nanotype and produce today’s shortest electron flash. to create cutting-edge laser pulses. The findings were recently published in a journal Nature.

Although it has long been known that light can release electrons from metals (Einstein was the first to explain how), this process is extremely difficult to manipulate. The electric field of light changes its direction about a million billion times per second, making it difficult to control how it strips electrons from the surface of metals.

To overcome this problem, the Rostock scientists and colleagues used a cutting-edge technology their group had previously developed – light field synthesis – that allowed them to reduce the burst of light to less than the full size of their field. In turn, they used these flashes to illuminate the tip of a tungsten needle to release electrons into space.

“Using light pulses that contain only one loop of their fields, it is now possible to deliver a precisely controlled shock to release electrons from the tungsten tip in a very short time interval,” explains Eleftherios Gulielmakis, leader of the research team. .

But this problem could not be overcome unless scientists also found a way to measure the short duration of these electron bursts. To overcome this hurdle, the team developed a new type of camera that can take snapshots of electrons as soon as a laser blasts them from the nanotype into a vacuum.

Lead author of the new study, Dr. “The trick was to use a second, very weak flash of light,” Hee-Yong Kim said. “This second laser flash can gently distort the energy of the electron explosion to see what it looks like over time,” he adds. “‘What’s in the box?’ “It’s like a game. Players try to identify an object without looking at it, but simply by turning it around by feeling its shape with their hands,” he continues.

But how can this technology be used in electronics? “As technology advances rapidly, it is reasonable to expect the development of microscopic electronic circuits in which electrons move in a space between tightly packed wires to avoid obstacles that slow them down,” says Gulielmakis. “Using light to eject electrons and move them between these wires could make future electronics several thousand times faster than today’s,” he explains.

However, the researchers believe that their newly developed methodology will be used directly for scientific purposes. “Removing electrons from a metal within a fraction of the light field cycle greatly simplifies experiments and allows us to use advanced theoretical methods to understand electron emission in a way that was previously impossible,” says Professor Thomas Fennell. to work. new release

“As our electron flashes provide excellent resolution to create snapshots of electronic and atomic motion in materials, we plan to use them to understand complex materials in depth to facilitate their application in technology,” concludes Gulielmakis.