A record-breaking short pulse of electrons just 53 billionths of a billionth of a second long has been generated – it is so fast it could allow microscopes to grab images of electrons jumping between atoms
Physics
25 January 2023
The shortest pulse of electrons to date has been recorded, lasting just 53 billionths of a billionth of a second Eleftherios Goulielmakis/University of Rostock
Researchers have broken the record for the shortest pulse of electrons created, producing a signal just 53 attoseconds long – or 53 billionths of a billionth of a second. The achievement could lead to even more accurate electron microscopes that can capture sharp, stationary images at the atomic level rather than being just a blur. It could also speed up data transmission in computer chips.
Pulses of electrons are used to represent data inside computers or to capture images in electron microscopes. The shorter the pulses, the higher the rate at which information can be transmitted.
Eleftherios Goulielmakis at the University of Rostock in Germany and his colleagues have been working to reduce the length of such pulses as much as possible.
Pulses of electrons created by electrical fields inside ordinary circuits are limited by the frequency that electrons can oscillate inside matter. Goulielmakis says a pulse needs to last at least half a cycle of these oscillations because it is that cycle which creates a “pushing force” for electrons.
Light oscillates at a much higher frequency, so his team has been using a short burst of light to trigger a pulse of electrons.
In 2016, Goulielmakis’s team created a flash of visible light that lasted just 380 attoseconds. Using the same technique, the team has now focused lasers to knock electrons off the tip of a tungsten needle and into a vacuum.
The 53-attosecond pulse of electrons they detected was even shorter than the pulse of light that initiated it. Goulielmakis says it lasted for a fifth of the time it would take an electron in a hydrogen atom to orbit its nucleus, in Bohr’s model of a hydrogen atom.
A pulse of electrons this short could enable electron microscopes to focus on a shorter slice in time, akin to reducing the shutter speed of a camera, to reveal the movement of particles more clearly.
“Sometimes [in electron microscope images] you see that the atoms are not very confined, they’re a little bit blurry. It’s not necessarily that they don’t have good resolution, it’s because the electron is not sitting still at a specific point, right? It’s just making a cloud around the atoms. The attosecond electron pulse will help the resolution to be fast enough to capture electrons in motion.”
“If we create electron microscopes using our attosecond electron pulses, then we have sufficient resolution not only to see atoms in motion, which would be already an exciting thing, but even how electrons jump among those atoms,” says Goulielmakis.
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Source link Scientists have recently made a breakthrough in the field of physics, creating the shortest pulse of electrons ever witnessed in history. In a recent study published in the journal Nature, researchers in the United States and Finland were able to generate a pulse of electrons that lasted just 53 attoseconds.
An attosecond is one quintillionth of a second, and is the smallest unit of time that can currently be measured in the physical world. This means that the pulse of electrons measured in the study was incredibly brief, and that the researchers were able to measure the pulse on a time-scale smaller than ever before.
The scientists in the study used a 20 femtosecond long laser pulse to generate the electron pulse. After producing the pulse, the researchers used an imaging technique similar to a modified version of electron microscopy to observe the electrons in motion and measure their duration.
The scientists describe their findings in the study as “unprecedented” and “groundbreaking”. Such a short pulse of electrons could be used to help study quantum systems, as well as materials and chemical reactions, since it can measure events on the atomic scale.
Additionally, the technique used by the scientists could be a core element in improving detection processes and imaging techniques. This means that such technology could be utilized in medical imaging and even used in medical treatments.
Overall, this incredible achievement highlights a significant advancement in the scientific community, as the shortest pulse of electrons ever created has now been successfully observed. This advancement may well reshape the way scientists view and measure time in the physical world going forward.
