A new means of producing three-dimensional light fields is allowing researchers to manipulate electrons into quantum states once thought impossible, according to newly published research.
The breakthrough, reported in a new study by physicists at the University of Oldenburg, points to new ways for scientists to control interactions between light and matter, as well as investigate quantum processes that could have significant implications for medicine and other fields.
According to the team behind the new research, their achievement involved the combination of two specially-shaped ultrashort bursts of light, known as femtosecond laser pulses, with each beam possessing a different color and lasting just a few millionths of a billionth of a second.
Directing these colored beams at a single point of intersection produced controllable light fields, which they say oscillate in all three spatial dimensions.
“With our method, we can generate electronic quantum states that have previously only been described theoretically and also make them spatially visible,” said Dr. Matthias Wollenhaupt, who led the recent research.
Using 3D-Light Fields to Excite Electrons
By leveraging three-dimensional light fields to selectively excite electrons present in potassium atoms, the researchers were able to demonstrate their new technique under conditions where the electrons are excited into significantly higher energy states before being released.
During this process, the researchers observed changes that occurred in very short intervals, allowing them a successful means of capturing the quantum evolution of these electrons as it occurred in stages—effectively resulting in a short “movie” of this underlying process.
The observations have several potentially useful applications, which include enabling new experiments in quantum physics. Going beyond just experimental uses, the team’s new technique may also have important applications in terms of the study of chiral molecules, which exist in two mirror-image forms that, much like human hands, can’t be superimposed.
A Question of Chirality
This asymmetrical quality of a structure and its “mirror” component, known as chirality, plays a significant role in biology and medicine, since different variations of a single molecule can often exhibit differences that are often dramatic.
Distinguishing between these molecular mirror images, therefore, presents a significant challenge for researchers.
In the past, theoretical research suggested that three-dimensional light fields can also possess apparent chiral properties, meaning that scientists may be able to leverage this quality to help distinguish between molecular forms with greater precision.
Fundamentally, the Oldenburg research team’s recent findings now establish an experimental foundation for applications in this area, thereby broadening the number of tools physicists have to help them manipulate matter at the quantum level.
“Our shaper-based approach establishes a route to fully controllable 3D light fields for chiral-sensitive light-matter interactions and ultrafast spectroscopy,” the team writes in their recent study.
The paper, “Multiphoton ionization with three-dimensional light fields,” was published in Physical Review Research.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.