Blackbody radiation shifts in optical atomic clocks

Area of Science:

• Atomic Physics
• Quantum Optics
• Theoretical Chemistry

Background:

• Optical atomic clocks are crucial for precise timekeeping and fundamental physics tests.
• Blackbody radiation (BBR) shifts are a significant source of uncertainty in optical clock frequencies.
• Accurate theoretical calculations are needed to minimize BBR shift effects.

Purpose of the Study:

• To review recent theoretical calculations of BBR shifts in optical atomic clocks.
• To present a new method for calculating BBR shifts in divalent atoms.
• To reduce uncertainties in atomic clock frequencies caused by BBR.

Main Methods:

• Review of relativistic all-order single-double (SD) method for monovalent ions.
• Development of a combined relativistic all-order and configuration interaction (CI) method for divalent atoms.
• Application of these methods to calculate BBR shifts in B+, Al+, and In+.

Main Results:

• Fractional uncertainties reduced to 4 × 10-19 for Al+ and 10-18 for B+ and In+ at room temperature.
• Calculated BBR shifts approach the precision limits of current optical atomic clock designs.
• The new method accurately treats correlation corrections in divalent atoms.

Conclusions:

• Theoretical advancements significantly reduce BBR shift uncertainties in optical clocks.
• The developed methods are vital for achieving next-generation atomic clock precision.
• Future work will focus on further reducing clock uncertainties from BBR shifts.