Black-body radiation shift of the Ga$^{+}$ clock transition

TL;DR

This paper calculates the blackbody radiation shift of the Ga$^+$ clock transition, finding it to be very small at room temperature, which is promising for precision timekeeping.

Contribution

The study provides the first detailed calculation of the blackbody radiation shift for the Ga$^+$ clock transition using configuration interaction methods.

Findings

Blackbody shift at 300K is -0.0140 ± 0.0048 Hz.

Small shift aligns with other group III ions.

Computed polarizabilities and low-lying spectrum of Ga$^{2+}$.

Abstract

The blackbody radiation shift of the Ga$^+$ $4s^2 \ ^1S^e_0 \to 4s4p \ ^3P^o_0$ clock transition is computed to be $-$$0.0140 \pm 0.0048$ Hz at 300 K. The small shift is consistent with the blackbody shifts of the clock transitions of other group III ions which are of a similar size. The polarizabilities of the Ga$^+$ $4s^2 \ ^1S^e_0$, $4s4p \ ^3P^o_0$, and $4s4p \ ^1P^o_1$ states were computed using the configuration interaction method with an underlying semi-empirical core potential. A byproduct of the analysis involved large scale calculations of the low lying spectrum and oscillator strengths of the Ga$^{2+}$ ion.