Trapped calcium ion clock achieves 1.5×10⁻¹⁵ fractional frequency uncertainty via GNSS satellite link to international time standard. Includes refined measurement of D₅/₂ Landé g-factor accounting for ac Zeeman shifts in ion trap electrodes.

Trapped calcium ion clock achieves 1.5×10⁻¹⁵ fractional frequency uncertainty via GNSS satellite link to international time standard. Includes refined measurement of D₅/₂ Landé g-factor accounting for ac Zeeman shifts in ion trap electrodes.