The blackbody radiation vibrational level shifts in the ground electronic state of N$_{2}^{+}$

Abstract

Homonuclear molecules have emerged as a crucial component in the pursuit of frequency standards, offering a promising avenue for the discovery of new physics phenomena that transcend the standard model. They also provide a unique approach to constraining variations in fundamental constants over time, thereby complementing the capabilities of atomic clocks. A notable challenge faced by molecular and single atomic quantum systems is the management of blackbody radiation (BBR), which introduces significant systematic errors and is challenging to regulate effectively. To address this issue, we perform {\it ab-initio} quantum chemical calculations to accurately determine the potential energy curve and the polarizability tensor for the ground state of the N$_2^+$ molecular ion, one of the most promising candidates for searching for variation of $m_{e}/m_{p}$ and creating frequency standards. We then calculate the BBR shifts affecting the vibrational levels of the ground electronic X$^2\Sigma_g^+$ state, marking a substantial contribution towards the precise experimental measurements.