Laser Cooling Scheme for the Carbon Dimer ($^{12}$C$_2$)

TL;DR

This paper proposes a laser cooling scheme for the carbon dimer ($^{12}$C$_2$), demonstrating the feasibility of cooling molecules with carbon-carbon bonds using specific electronic transitions, potentially enabling quantum control of organic molecules.

Contribution

It introduces a detailed laser cooling scheme for $^{12}$C$_2$, including calculations of branching ratios and photon scattering, showing practical implementation possibilities.

Findings

Cooling via Swan and Duck bands is achievable with current techniques.

Narrow-line cooling potential exists through Phillips and Ballik-Ramsay bands.

The scheme enables laser cooling of molecules with carbon-carbon bonds.

Abstract

We report on a scheme for laser cooling of $^{12}$C$_2$. We have calculated the branching ratios for cycling and repumping transitions and calculated the number of photon scatterings required to achieve deflection and laser cooling of a beam of $C_2$ molecules under realistic experimental conditions. Our results demonstrate that C$_2$ cooling using the Swan ($d^3\Pi_\text{g} \leftrightarrow a^3\Pi_\text{u}$) and Duck ($d^3\Pi_\text{g} \leftrightarrow c^3\Sigma_\text{u}^+$) bands is achievable via techniques similar to state-of-the-art molecular cooling experiments. The Phillips ($A^1\Pi_\text{u} \leftrightarrow X^1\Sigma_\text{g}^+$) and Ballik-Ramsay ($b^3\Sigma_\text{g}^- \leftrightarrow a^3\Pi_\text{u}$) bands offer the potential for narrow-line cooling. This work opens up a path to cooling of molecules with carbon-carbon bonds and may pave the way toward quantum control of organic molecules.