, has now measured this exotic atomic bond for the first time. This interaction can be used to manipulate atoms that are incredibly cold, and the effect may also have a role in how molecules form in space. The findings were recently published inA positively charged atomic nucleus is surrounded by negatively charged electrons in an electrically neutral, which surrounds the atomic nucleus like a cloud.
Because light is just an electromagnetic field that changes extremely quickly, this polarization effect may also be achieved with laser light. When many atoms are located near one another, the laser light polarizes them all precisely in the same manner, either with positive on the left and negative on the right, or the other way around. Both times, two neighboring atoms move their opposing charges in the direction of one another, creating an attractive force.
The atoms are first captured and cooled in a magnetic trap on an atom chip, a technique, which was developed at the Atominstitut in the group of Professor Jörg Schmiedmayer. Then the trap is switched off and releases the atoms in free fall. The atom cloud is ‘ultracold’ at less than a millionth of a Kelvin, but it has enough energy to expand during the fall.
This attractive force is a complementary tool for controlling cold atoms. But it could also be important in astrophysics: “In the vastness of space, small forces can play a significant role,” says Philipp Haslinger. “Here, we were able to show for the first time that electromagnetic radiation can generate a force between atoms, which may help to shed new light on astrophysical scenarios that have not yet been explained.
Reference: “Observation of Light-Induced Dipole-Dipole Forces in Ultracold Atomic Gases” by Mira Maiwöger, Matthias Sonnleitner, Tiantian Zhang, Igor Mazets, Marion Mallweger, Dennis Rätzel, Filippo Borselli, Sebastian Erne, Jörg Schmiedmayer and Philipp Haslinger, 27 July 2022,