Electrostatic deflection of a molecular beam of massive neutral particles: Fully field-oriented polar molecules within superfluid nanodroplets

TL;DR

This study demonstrates that superfluid helium nanodroplets enable full orientation and measurable deflection of massive neutral polar molecules, allowing direct determination of molecular dipole moments.

Contribution

The paper introduces a novel method using superfluid nanodroplets for full orientation and deflection of large neutral polar molecules, including complex and biological ones.

Findings

Enables full orientation of molecules within superfluid droplets.

Allows measurable deflection of large, neutral, doped nanodroplets.

Facilitates direct measurement of molecular dipole moments.

Abstract

Electric deflection measurements on liquid helium nanodroplets doped with individual polar molecules demonstrate that the cold superfluid matrix enables full orientation of the molecular dipole along the external field. This translates into a deflection force which is increased enormously by comparison with typical deflection experiments, and it becomes possible to measurably deflect neutral doped droplets with masses of tens to hundreds of thousands of Daltons. This approach permits preparation and study of continuous fluxes of fully oriented polar molecules and is broadly and generally applicable, including to complex and biological molecules. It is shown that the dipole moments of internally cryogenically cold molecules can be directly determined from a deflection measurement on the doped nanodroplet beam.