Subwavelength stabilization of polar-molecule pairs

Establish experimental methods for stabilizing pairs of microwave-shielded polar molecules at the deeply subwavelength separations required to access the interaction-dominated cavity-QED regime, extending nanoscale-confinement techniques from dipolar atomic systems to polar molecules.

Background

The proposed interaction-enhanced photon blockade relies on two microwave-shielded polar molecules separated by approximately 84.6 nm, or 1600 Bohr radii. At this deeply subwavelength distance, the shielding interaction is much larger than the cavity linewidth and generates the spectral anharmonicity needed for strong photon blockade and Bell-state protection.

Although optical-tweezer experiments have achieved deterministic preparation, coherent control, and entanglement of individual polar molecules at programmable micrometer-scale separations, maintaining molecular pairs at the much shorter distances required by the proposed cavity-QED scheme is experimentally difficult. The paper points to nanoscale confinement techniques developed for dipolar atomic systems as a possible route, while explicitly identifying their extension to polar molecules as an unresolved challenge.

References

Nevertheless, stabilizing molecular pairs at the deeply subwavelength separation considered here remains experimentally challenging. Recent advances toward nanoscale confinement in dipolar atomic systems suggest possible routes toward accessing such interaction-dominated configurations, although extending these techniques to polar molecules remains an important open challenge.

— Interaction-enhanced photon blockade and Bell-state protection in microwave-shielded polar molecules  (2610.09959 - Chen et al., 7 Oct 2026) in Section "Model and Hamiltonian", paragraph following the discussion of the short-range subwavelength regime