Polyatomic Molecules as Quantum Sensors for Fundamental Physics

Abstract

Precision measurements in molecules have advanced rapidly in recent years through developments in techniques to cool, trap, and control. The complexity of molecules makes them a challenge to study, but also offers opportunities for enhanced sensitivity to many interesting effects. Polyatomic molecules offer additional complexity compared to diatomic molecules, yet are still "simple" enough to be lasercooled and controlled. While laser cooling molecules is still a research frontier itself, there are many proposed and ongoing experiments seeking to combine the advanced control enabled by ultracold temperatures with the intrinsic sensitivity of molecules. In this perspective, we discuss some applications where laser-cooled polyatomic molecules may offer advantages for precision measurements of fundamental physics, both within and beyond the Standard Model.

Complete Controllability Despite Degeneracy: Quantum Control of Enantiomer-Specific State Transfer in Chiral Molecules

“…ionizing all molecules in one of the two levels. High-resolution searches of parity violation would also benefit from enantiomer-selective population excitation [10,13,14]. However, at most a few per cent of enantiomer selectivity have so far been observed [10][11][12] in experiments that were all based on resonant phasesensitive microwave three-wave mixing [2][3][4].…”

Searches for new sources of CP violation using molecules as quantum sensors

“…Molecules, on the other hand, have only recently surpassed the sensitivity of atomic measurements in a few key areas. Compared to atoms, the larger polarizability and internal fields of molecules results in up to a thousand-fold increase in sensitivity to fundamental symmetry violations such as electron EDMs, CPV electron-nucleon interactions, and hadronic CPV [1,2,[4][5][6]. Though the complexity of molecules makes them challenging to control, the inherent advantages of their complex structure far outweighs this drawback.…”

$\mathcal{P}$,$\mathcal{T}$-odd effects for RaOH molecule in the excited vibrational state

“…Both the possibility of laser cooling and the existence of the close levels of the opposite parity can be realized with triatomic molecules such as RaOH [18], YbOH [19] etc. In this case the role of the Ω-doublets used in the diatomic molecular experiments is overtaken by the ldoublets [19,20]. Let us elucidate the nature of these levels and their importance for the search of P, T violation.…”