The methods of laser cooling of atoms have already long been applied to obtain cold and ultracold atomic gases, including degenerate states, in particular, an atomic Bose—Einstein condensate. The application of laser cooling methods to molecules was assumed until recently to be impossible because of the complex structure of molecular levels and the absence of closed cooling cycles for transitions between electronic levels of molecules in the general case. However, it has recently become clear that laser cooling can be performed for a large class of molecules, including not only the simplest diatomic molecules but also polyatomic molecules. The review presents the general principles for identifying suitable molecules and discusses current studies on and further developments in the laser cooling of molecules.

Correspondence should be addressed to Keywords: cold molecules, spectroscopy, laser cooling, electronic structure PACS: 31.10.+z, 33.20.−t, 37.10.De (all) DOI: 10.3367/UFNe.2018.12.038509 URL: https://ufn.ru/en/articles/2020/3/d/ 000537856300004 2-s2.0-85086632398 2020PhyU...63..289I Citation: Isaev T A "Direct laser cooling of molecules" Phys. Usp. 63 289–302 (2020) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 14th, September 2018, revised: 18th, December 2018, accepted: 26th, December 2018 Оригинал: Исаев Т А «Прямое лазерное охлаждение молекул» УФН 190 313–328 (2020); DOI: 10.3367/UFNr.2018.12.038509