Blue-detuned magic wavelength for thulium

Determine the blue-detuned magic wavelength for thulium atoms, considering wavelengths near the 410 nm and 506 nm laser-cooling transitions or around 390 nm, to enable the development of all-optical thulium atom-chip clocks.

Background

The paper proposes thulium as a promising candidate for all-optical atom-chip clocks because its inner-shell magnetic-dipole clock transition has an exceptionally small differential scalar polarizability and a very small differential van der Waals coefficient. A red-detuned magic wavelength at 813.32 nm has already been identified, but the corresponding blue-detuned magic wavelength remains unresolved. Identifying it is important for designing trapping configurations that suppress differential frequency shifts and could support clock accuracies in the range of 10-17 to 10-18.

References

Although it is clear that the blue-detuned magic wavelength for thulium atoms should be searched for on either side of the laser cooling transitions at 410\,nm and 506\,nm, or around 390\,nm as with strontium atoms, it has not yet been identified.

— Optical atomic clocks on all-optical atom chips  (2610.13701 - Ovchinnikov, 9 Oct 2026) in Outlook