original version of this story Appeared in Quanta Magazine.
To glimpse the unimaginably fast particles of the subatomic world, we must generate unimaginably short flashes of light. Anne L’Huillier, Pierre Agostini, and Ferenc Krausz shared: 2023 Nobel Prize in Physics For pioneering research that has developed the ability to illuminate reality on almost inconceivably short time scales.
From the 1980s to the early 2000s, three physicists developed a technique to generate laser pulses that were just attoseconds long, billions of times shorter than a second. Seen in such short flashes, the world slows down. The beat of a hummingbird’s wings becomes eternal. Even the constantly flying atoms become dull. On the attosecond timescale, physicists can directly detect the movement of electrons themselves as they fly around atoms and from place to place.
“The ability to generate attosecond pulses of light opens the door on very small time scales. It also opens the door to the world of electrons.” Eva OlsonChairman of the Nobel Committee for Physics, physicist at Chalmers University of Technology.
In addition to being a fundamentally new way to study electrons, this way of seeing the world in super slow motion could lead to many applications. Mats LarssonThe Nobel Prize committee member credited the technology with launching the field of “atochemistry,” or the ability to manipulate individual electrons using light. He also said that when semiconductors are exposed to attosecond laser pulses, the material switches almost instantly from blocking the flow of electricity to conducting it, potentially enabling the fabrication of ultrafast electronic devices. Stated. And Krausch, one of this year’s recipients, is also harnessing the power of attosecond pulses to detect subtle changes in blood cells that can signal early stages of cancer.
The world of hyperspeed is very different from ours, but thanks to the work of researchers like Lhuillier, Agostini, Krauss, and others, we’re just beginning to see it.
What is an attosecond?
One attosecond is one quintillionth of a second, or 0.000000000000000001 second. The number of attoseconds that pass in one second is greater than the number of seconds that have passed since the creation of the universe.
Illustration: Merrill Sherman/Quanta Magazine
To measure the movements of planets, we think in terms of days, months, and years. To measure his 100 meter run, a human would use 1 second or 1/100th of a second. However, as we dive deeper into the microscopic world, objects move faster. To measure near-instantaneous movements, such as dancing electrons, you need a stopwatch with a much finer scale: the attosecond.
In 1925, Werner Heisenberg, one of the pioneers of quantum mechanics, argued that the time it takes an electron to complete one orbit around a hydrogen atom cannot be observed. In a sense, he was right. Electrons do not orbit the nucleus the way planets orbit stars. Rather, physicists understand them as probability waves that give a probability of being observed at a particular place and time, so you can’t literally measure electrons flying through space.
But in another sense, Heisenberg underestimated the ingenuity of 20th century physicists like Lhuillier, Agostini, and Krauss. The probability of an electron being there or there changes from attosecond to attosecond. It can also generate attosecond laser pulses that can interact with electrons as they evolve, allowing researchers to directly study the behavior of different electrons.
How do physicists generate attosecond pulses?
In the 1980s, Ahmed Zewail at the California Institute of Technology developed the ability to strobe lasers with pulses lasting a few femtoseconds (thousands of attoseconds). These blips, which earned Zweil the 1999 Nobel Prize in Chemistry, were enough for researchers to study how chemical reactions occur between atoms within molecules. The advance payment was charged as ‘.world’s fastest camera”
For a while, faster cameras seemed impossible. It wasn’t clear how to make light oscillate any faster. However, in 1987, Anne Lhuillier and his collaborators interesting observation: When you shine light on a certain gas, its atoms become excited and re-emit additional colors of light that vibrate many times faster than the original laser. This is an effect known as “overtones.” Lhuillier’s group found that in gases like argon, some of these extra colors appear brighter than others, but the pattern is unexpected. At first, physicists didn’t know what to make of this phenomenon.
