What if scientists can synthesize triatomic molecules under quantum restrictions? Direct cooling of triatomic molecules is extremely difficult due to the complex vibrational and rotational energy levels of molecules. Therefore, the group embraced a different method by combining ultracold atom with diatomic particles to yield ultracold triatomic particles.
Radio-Frequency Pulse Enables Association of Triatomic Molecules in Ultracold 23Na40K+ 40K Gas
Three-body system is already formidable in classical physics, not to discuss the quantum state three-body system. But what if scientists can manufacture triatomic particles under quantum restrictions? It might serve as a suitable platform to study three-body prospective energy surface which is important but tough to calculate.
Just Recently, Prof. PAN Jianwei and Prof. ZHAO Bo from the University of Science and Technology of China (USTC), working together with Prof. BAI Chunli from Institute of Chemistry of the Chinese Academy of Sciences, discovered strong proof for association of triatomic particles after applying a radio-frequency (rf) pulse to an ultracold mix of 23Na40K and 40K near Feshbach resonance. The work was published in the journal Nature.
Direct cooling of triatomic molecules is extremely difficult due to the complex rotational and vibrational energy levels of molecules. Therefore, the group embraced a different method by combining ultracold atom with diatomic molecules to yield ultracold triatomic particles. Nevertheless, due to the weak coupling strength, an atom– diatomic-molecule Feshbach resonance ought to be presented in order to boost molecular association, which is tough owing to the intricacy and intricacy of Feshbach resonance.
In this work, scientists tuned the Feshbach resonance by using external rf fields and effectively combined the triatomic bound state and atom-diatomic-molecule scattering state.
The association of triatomic molecules was evidenced by rf loss spectrum: the rf spectrum displayed additional loss with fewer 23Na40K molecules in the system, and the loss of 23Na40K suggested the formation of triatomic particles. The triatomic molecules had a short lifetime, the association signal might still be gotten, as was one benefit of rf pulse.
By examining the rf spectrum, scientists approximated the binding energy of triatomic particle by embracing a universal relation close to the resonance point. The result showed a strong binding obtained from the interaction between the scattering state and the bound state.
This work pioneered the association of triatomic molecules and led the way for ultracold chemical physics and quantum simulation with particles.
Referral: “Evidence for the association of triatomic molecules in ultracold 23Na40K+ 40K mixes” by Huan Yang, Xin-Yao Wang, Zhen Su, Jin Cao, De-Chao Zhang, Jun Rui, Bo Zhao, Chun-Li Bai & & Jian-Wei Pan, 9 February 2022, Nature.DOI: 10.1038/ s41586-021-04297-2.
