cooling molecules
cooling molecules

IMM researchers create Bose-Einstein condensate of molecules

Researchers from the Institute for Molecules and Materials (IMM) at Radboud University, in collaboration with researchers from Columbia University (USA) have created the first BEC of polar molecules, which gives access to a quantum gas with strong dipole-dipole interactions, and can be used for quantum technologies. Their results are published in Nature.

Bose-Einstein condensation occurs in a gas of atoms or molecules when the temperature is so low that their wavefunctions overlap. When this happens, a phase transition occurs, and the particles condense into the quantum mechanical ground state. This results in a macroscopic system described by a single wavefunction. Interactions between particles in this "quantum gas’’ can be fully controlled. The many-particle quantum system with tunable interactions can then be used to emulate poorly understood systems, such as electrons in quantum materials. This technology is called quantum simulation.

Cooling molecules

BECs of atoms were first realized in 1995. Achieving Bose-Einstein condensation of molecules has been more challenging due to collisional losses. Until now. The researchers are now able to control these collisions. This enables efficient cooling of the molecules to below the phase transition to the BEC, marking the first observation of a phase transition in a gas of ultracold molecules.  The experiment has been performed in the group of Professor Sebastian Will (Columbia University, USA).

Quantum physics 

The ability to control molecular interactions and stabilize molecular BECs opens up new possibilities for quantum simulation. With this new BEC, scientists are able manipulate the strength of interactions between the molecules in the condensate, from very weak to very strong. This enables emulating strongly-interacting electrons in quantum materials more closely. The molecular BEC is also a powerful platform to study dipolar quantum many-body physics. Such studies are vital for uncovering novel quantum phenomena and have profound implications in physics, potentially leading to the creation of innovative materials and new technologies.

evaporative cooling
Literature reference

Observation of Bose-Einstein Condensation of Dipolar Molecules
Niccolò Bigagli, Weijun Yuan, Siwei Zhang, Boris Bulatovic, Tijs Karman, Ian Stevenson, and Sebastian Will
Nature (2024)
DOI: 10.1038/s41586-024-07492-z

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