ERC Advanced Grant for studies on ultracold molecular collisions

Bas van de Meerakker, Professor in Spectroscopy of Cold Molecules within the Institute for Molecules and Materials (IMM) at Radboud University has been awarded an ERC Advanced Grant of 3.3 million Euros to work on project QUCUMBER.

The project aims to study collisions between atoms and molecules at very low temperatures to elucidate the quantum mechanics underlying molecular interactions and will test existing quantum theories. ERC Advanced funding is amongst the EU’s most prestigious and competitive, providing leading senior researchers with the opportunity to pursue ambitious, curiosity-driven projects that could lead to major scientific breakthroughs. The researchers can use the grant for the employment of PhD’s and Postdocs as well as the development of infrastructure to continue their research for the next five years. 

Van de Meerakker: “I am pleased with this grant as it allows us to develop new methods to probe molecular interactions deeply into the quantum regime, where many interesting phenomena are expected to occur that thus far have remained elusive experimentally. I am particularly pleased as nowadays it is quite difficult to obtain funding for curiosity-driven fundamental research projects like ours. This ERC grant allows us to learn about molecular collisions and interactions at the most fundamental level, and this may become very important for future applications not foreseeable now.”

Spectroscopy of cold molecules 
Van de Meerakker is an expert in the field of experimental Chemical Physics. He is head of the Spectroscopy of Cold Molecules group, which is part of IMM. He studies molecular collisions, a process that happens all around us in environments ranging from the earth’s atmosphere to interstellar space, but that is still not completely understood. ‘Take two oxygen molecules in our atmosphere, nobody knows what happens exactly when they interact with each other. The problem lies in the many degrees of freedom of molecules, there are infinite ways in which they can interact. Even the best theorists cannot solve this problem exactly’, Van de Meerakker explains. The group aims to tackle this problem practically by colliding neutral molecules at the lowest possible temperatures. At low temperatures the number of degrees of freedom reduces, giving the unique opportunity to directly observe what is going on. 

Reducing collision energy 
In addition, at low temperatures matter starts behaving like quantum waves revealing fundamental aspects of collisions, leading to new phenomena that simply do not occur at higher energies. Therefore,  there currently is a large interest to study molecular collisions with the highest possible level of detail, and at the lowest possible temperatures. Crossed beam methods allow for detailed observation of these collisions, but current technologies are not sufficient to reach the low temperatures that are required to fully explore these phenomena. In the QUCUMBER project, based on his latest breakthrough in state-to-state merged beam scattering at record-low energies, Van de Meerakker will develop new methods to reduce the currently attainable temperature with an additional 2-3 orders of magnitude. He will study how molecules interact using a combination of Stark deceleration, merged beams, laser cooling and velocity map imaging. Using two different systems that are characteristic for a large class of molecular interactions, Van de Meerakker will measure quantum properties in the state-to-state integral and differential cross sections. 

With this project, we hope to reach temperatures of 100 µK. This will bring us in the pure quantum regime, a bizarre energy range where our current understanding of chemistry completely breaks down, and descriptions using pure matter waves are required. We will be able to directly visualize how nature transforms from high temperatures where classical mechanics dominates into the pure quantum world at temperatures approaching zero Kelvin. Nobody exactly knows how these two worlds connect, and I am thrilled that we now have the opportunity to figure it out.”

From hot to cold 
The research project will provide a direct glimpse into how molecular interactions transform from high energies into the ultracold, opening routes for more and better understanding of quantum theories of molecular interactions. At low temperatures, it will also allow the researchers to start manipulating the collisions using electric fields. Developing such a control knob that one can turn on to steer the outcome of a collision at will gives enormous possibilities for future research directions. ‘This project will connect the two fields of ultracold quantum physics and physical chemistry, and will establish new phases in the understanding and control of molecular collision processes.’, Van de Meerakker concludes.

ERC Advanced Grant
The ERC Advanced Grant of the European Research Council (ERC) are annually granted to senior researchers for exceptional, innovative and ground-breaking research. The European Research Council stimulates high-risk, blue-sky frontier research in Europe by competitive funding in various disciplines, based on scientific excellence. The ERC Advanced grants are part of the EU’s Horizon Europe programme and focused at supporting researchers of any nationality who have a track record of significant research achievements in the last ten years.

We warmly congratulate Bas with his grant!

Bas van de Meerakker

Bas van de Meerakker
Bas van de Meerakker

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Molecules and materials, Science