Optical Pumping of TeH+: Implications for the Search for Varying mp/me

Abstract

Molecular overtone transitions provide optical frequency transitions sensitive to variation in the proton-to-electron mass ratio ($\mu\equiv m_p/m_e$). However, robust molecular state preparation presents a challenge critical for achieving high precision. Here, we characterize infrared and optical-frequency broadband laser cooling schemes for TeH$^+$, a species with multiple electronic transitions amenable to sustained laser control. Using rate equations to simulate laser cooling population dynamics, we estimate the fractional sensitivity to $\mu$ attainable using TeH$^+$. We find that laser cooling of TeH$^+$ can lead to significant improvements on current $\mu$ variation limits.