Optical clock sensitive to variations of the fine-structure constant based on the ${\text{Ho}}^{14+}$ ion

We study the ${\mathrm{Ho}}^{14+}$ ion as a candidate for an extremely accurate and stable optical atomic clock which is sensitive to the time variation of the fine-structure constant. We demonstrate that the proposed system has all the desired features including relatively strong optical electric-dipole and magnetic-dipole transitions which can be used for cooling and detection. Zero quadrupole moments for the relevant states in the clock transition allow interrogation of multiple ions to improve the clock stability.

Figure 1

Low-lying energy levels of ${\mathrm{Ho}}^{14+}$. Numbers in parentheses correspond to those in Tables 2 and 4 to denote electronic states.