Frequency measurement of the transition of 27Al+ via quantum logic spectroscopy with 40Ca+

Abstract

We perform quantum logic spectroscopy with a ^27 Al ^+ / ^40 Ca ^+ mixed ion crystal in a linear Paul trap for a measurement of the ${(3{s}^{2}){}^{1}{{\rm{S}}}_{0}\leftrightarrow (3s3p)}^{3}{{\rm{P}}}_{1},F=7/2$ intercombination transition in ^27 Al ^+ . Towards this end, Ramsey spectroscopy is used for probing the transition in ^27 Al ^+ and the $(4{s}^{2}){{\rm{S}}}_{1/2}\leftrightarrow \,(4s3d){{\rm{D}}}_{5/2}$ clock transition in ^40 Ca ^+ in interleaved measurements. By using the precisely measured frequency of the clock transition in ^40 Ca ^+ as a frequency reference, we determine the frequency of the intercombination line to be ${\nu }_{{}^{1}{{\rm{S}}}_{0}\leftrightarrow {}^{3}{{\rm{P}}}_{1},F=7/2}$ = 1 122 842 857 334 736 (85) Hz and the Landé g -factor of the excited state to be ${g}_{{}^{3}{{\rm{P}}}_{1},F=7/2}$ = 0.428 133(2).

Keywords

• trapped ions
• mixed ion crystals
• quantum logic spectroscopy
• frequency standard
• metrology