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Magnetic Deflection of High-Spin Sodium Dimers Formed on Helium Nanodroplets
Thomas H Villers1, Benjamin S Kamerin1, Vitaly V Kresin1
1Department of Physics and Astronomy, University of Southern California; Los Angeles, California 90089-0484, United States.
The Journal of Physical Chemistry Letters
|April 29, 2025
Summary
Alkali-atom dimers on liquid helium nanodroplets are mainly in a spin-triplet state. Magnetic deflection confirms abundant high-magnetic-moment dimers whose spins orient with the field.
Area of Science:
- Atomic and Molecular Physics
- Low-Temperature Physics
- Surface Science
Background:
- Alkali-atom dimers on liquid helium nanodroplets are typically observed in a metastable, spin-triplet state.
- Understanding the magnetic properties of these dimers is crucial for their manipulation and application.
Purpose of the Study:
- To experimentally demonstrate the abundance of high-magnetic-moment alkali-atom dimers on liquid helium nanodroplets.
- To investigate the spin dynamics and orientation of these dimers within the superfluid droplet environment.
Main Methods:
- Utilizing a magnetic Stern-Gerlach deflection technique on a beam of sodium-doped liquid helium nanodroplets.
- Measuring the deflection patterns to infer the magnetic moments and spin states of the dimers.
Main Results:
- Transparently demonstrated the prevalence of alkali-atom dimers with significant magnetic moments.
- Showcased that the electron spins of these dimers readily thermalize with the cryogenic droplet.
- Confirmed that the dimer spins become fully oriented by an external magnetic field.
Conclusions:
- Liquid helium nanodroplets provide a unique environment for stabilizing and manipulating alkali-atom dimers in specific spin states.
- The observed spin-triplet state and high magnetic moments are key characteristics of these surface-bound dimers.
- External magnetic fields can effectively control the spin orientation of alkali-atom dimers on superfluid helium.
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