Scientists synthesize triatomic molecules for the first time in an ultra-cold mixture of atoms丨 Nature

Pan Jianwei and Zhao Bo of the University of Science and Technology of China cooperated with the Bai Chunli group of the Institute of Chemistry of the Chinese Academy of Sciences to synthesize triatomic molecules for the first time in the mixture of ultracold atoms and molecules, taking an important step towards quantum simulation based on ultracold atomic molecules and the research of ultracold quantum chemistry. The results were published in Nature on February 10.

Quantum computing and quantum simulation have powerful parallel computing and simulation capabilities, which can not only solve computational problems that classical computers cannot handle, but also effectively reveal the laws of complex physical systems, thereby providing guidance for new energy development and new material design. The use of highly controllable ultra-cold quantum gases to simulate complex and difficult to calculate physical systems can accurately study complex systems, so it has broad application prospects in chemical reactions and new material design.

Ultracold molecules will open up new ideas for quantum computing and provide an ideal platform for quantum simulations. However, due to the complexity of the vibrational rotational energy levels inside the molecules, it is very difficult to prepare ultracold molecules by direct cooling. The development of ultracold atom technology provides a new way to prepare ultracold molecules. One can bypass the difficulty of direct cooling molecules and synthesize molecules from ultra-cold atomic gas using lasers and electromagnetic fields. Synthesizing triatomic molecules from a mixture of atoms and diatomic molecules is an important research direction in the field of synthetic molecules.

The Research Team at the University of Science and Technology of China observed the Feshbach resonance of atoms and diatomic molecules at ultra-low temperatures for the first time in 2019. Near the Feshbach resonance, the energies of the bound state of the triatomic molecules tend to coincide with the energy of the scattering state, while the coupling between the scattered and bound states is greatly enhanced by resonance. The successful observation of the resonance of atomic molecules Feshbach provides new opportunities for the synthesis of triatomic molecules.

In this study, the collaborative research team successfully achieved the synthesis of triatomic molecules using radio frequency field coherence for the first time. In the experiment, they prepared sodium-potassium ground-state molecules in a single ultra-fine state from an ultra-cold atomic mixture close to absolute zero. Near the Feshbach resonance of potassium atoms and sodium-potassium molecules, the scattered states of atomic molecules and the bound states of triatomic molecules are coupled together by an RF field. They successfully observed the signal of the RF synthesis triatomic molecule on the rf loss spectrum of the sodium-potassium molecule and measured the binding energy of the triatomic molecule near the Feshbach resonance. The results open up a new path for quantum simulation and ultracool chemistry research.

Related thesis information: https://doi.org/10.1038/s41586-021-04297-2

Source: China Science News