Introduction
4He nanodroplet isolation
Matrix isolation spectroscopy in cryogenic environment is an important technique to investigate properties of a molecule at low temperature. Our group make use of He nanodroplet isolation
(HENDI) technique aiming at production of ultracold molecules and/or complexes as well as research of their dynamics.
The rapid cooling is the first key of utilizing HENDI. Molecules picked up in superfluid He droplets reach at 0.4 K in 0.1 ms via evaporative cooling, which enables us to assemble single or clusters of molecules at their lowest energy level in the droplets. Another significant aspect of HENDI is its high-resolution capability in spectroscopy. By virtue of the frictionless environment in superfluid He, molecules embedded in He droplets rotate freely as in the gas phase, which provides rotational fine structures in their spectra. Clearly, HENDI method holds
great promise for the study of ultracold molecules.
Our HENDI apparatus which includes CW or pulsed nozzle, two pickup cells and QMS is exhibited below. Currently we employ OPO laser as a source of IR photon to observe well resolved spectra of cold molecules and clusters. Ongoing experiments include spectroscopy of chiral molecules and their clusters for the study of chiral-chiral interactions, and spectroscopy of clusters of H2 molecules for the exploration of molecular superfluidity.
HENDI experiment