229Thorium-doped calcium fluoride for nuclear laser spectroscopy

Area of Science:

• Nuclear Physics
• Atomic Physics
• Materials Science

Background:

• The low-energy nuclear isomer of thorium-229 (229Th) offers a unique system for laser-based manipulation of nuclear quantum states.
• Implanting 229Th into vacuum ultraviolet (VUV) transparent crystals is proposed for laser spectroscopy and a solid-state nuclear clock.

Purpose of the Study:

• To computationally validate the feasibility of doping thorium into calcium fluoride (CaF2) single crystals.
• To investigate the electronic structure and optical properties of thorium-doped CaF2 for nuclear transition interrogation.

Main Methods:

• Atomistic modeling and simulation.
• First-principles electronic structure calculations.
• Band gap analysis and defect level investigation.

Main Results:

• Computer modeling confirmed a persistent large band gap in thorium-doped CaF2.
• No new electronic levels were found within the band gap, indicating suitability for optical interrogation.
• Estimation of thorium nuclear quantum levels within the solid-state environment.

Conclusions:

• Thorium doping in CaF2 crystals is a feasible approach for laser spectroscopy of nuclear transitions.
• This solid-state system enables direct optical interrogation of the 229Th nuclear isomer.
• The findings support the development of optical Mössbauer spectroscopy and solid-state nuclear clocks.