Physicists Just Found a Way to Control Atoms Using Twisted Light

By Bernard Rizk, University of Ottawa March 18, 2025

Collected at: https://scitechdaily.com/physicists-just-found-a-way-to-control-atoms-using-twisted-light/

Scientists have unlocked a new way to control ionization, the process where atoms lose electrons, using specially designed light beams

By leveraging optical vortex beams, light that carries angular momentum, they can precisely dictate how electrons break free from atoms. This discovery could reshape imaging technology, enhance particle acceleration, and open doors to advancements in quantum computing.

Unlocking the Secrets of Ionization

Atoms are the fundamental building blocks of everything around us. Occasionally, they lose electrons and become charged particles, a process known as ionization. This phenomenon occurs in lightning, plasma TVs, and even the northern lights. Until now, scientists believed their ability to control ionization was quite limited.

A research team led by Ravi Bhardwaj, Full Professor at the University of Ottawa’s Department of Physics, and PhD student Jean-Luc Begin, in collaboration with Professors Ebrahim Karimi, Paul Corkum, and Thomas Brabec, has introduced a groundbreaking method to manipulate ionization using specially structured light beams.

Optical Vortex Beams – A New Approach

Ionization plays a key role in strong field physics and attosecond science, governing how electrons break free from their atomic bonds. Traditionally, scientists thought this process had strict limitations on how much it could be controlled. However, this new study challenges that belief.

“We have demonstrated that by using optical vortex beams—light beams that carry angular momentum—we can precisely control how an electron is ejected from an atom,” explains Professor Bhardwaj. “This discovery opens up new possibilities for enhancing technology in areas such as imaging and particle acceleration.”

Experimenting with Light and Electrons

The research took place over two years at uOttawa’s Advanced Research Complex. The team found that the handedness and properties of the optical vortex beams significantly affect ionization rates. By adjusting the position of a “null intensity region” within the beam, they achieved selective ionization, introducing a novel concept called optical dichroism.

Key Findings and Game-Changing Discoveries

1. The first demonstration of ionization that depends on the properties of light beams carrying angular momentum.
2. Enhanced control over ionization processes that could lead to advancements in imaging techniques beyond current limitations.
3. A new understanding of how light can be engineered to influence the behavior of electrons in unprecedented ways.

“We have demonstrated that by using optical vortex beams, light beams that carry angular momentum, we can precisely control how an electron is ejected from an atom”

Ravi Bhardwaj, Full Professor at uOttawa’s Department of Physics

The Future of Ionization Control

This work builds upon foundational theories in the field and has the potential to revolutionize how scientists approach ionization. This isn’t just for physics textbooks – it could lead to better medical imaging, faster computers, and more efficient ways to study materials. It’s especially promising for quantum computing, where controlling individual particles is crucial.

Professor Bhardwaj emphasizes the importance of this breakthrough: “Changing the way we think about how electrons are ejected has been challenging, but our research proves that using advanced laser technologies can lead to new discoveries that impact both science and technology.”

Reference: “Orbital angular momentum control of strong-field ionization in atoms and molecules” by Jean-Luc Bégin, Ebrahim Karimi, Paul Corkum, Thomas Brabec and Ravi Bhardwaj, 12 March 2025, Nature Communications.
DOI: 10.1038/s41467-025-57618-8