$^{138}$Ba$^{+}$ Zeeman qubit operation through Raman transition

Barium (Ba) and Ytterbium (Yb) are excellent candidates to perform sympathetic cooling [1] due to the relatively small mass difference between those species. It is possible to reach Doppler cooling limit for the Ba-Yb linear ion chain of multiple ions [2]. Here $^{138}$Ba$^{+}$ is used as an informational qubit. We drive $6S_{1/2}-6P_{1/2}$ Raman transitions with a 532 nm mode-locked laser to perform qubit operations and use the narrow $6S_{1/2}-6D_{5/2}$ quadrupole transition for state detection and initialization. Starting with a linear chain of Ba ions, we discuss the possibility to incorporate $^{174}$Yb$^{+}$ ions to perform sympathetic cooling. [1] D. Kielpinski et al., Phys. Rev. A 61, (2000) [2] T. P. Sakrejda, L. Zhukas, B. B. Blinov arXiv:1809.00240 [physics.atom-ph]