Simultaneous Enantiomer-Resolved Ramsey Spectroscopy Scheme for Chiral Molecules

Abstract

Chiral molecules provide an ideal test platform to search for symmetry breaking in nature, due to the perfect parity symmetry of their left- and right-handed enantiomers under the electromagnetic interaction. This high degree of symmetry drives efforts to probe the two enantiomers individually after they have been chemically separated, but this allows external effects to influence the measurement, ultimately harming the precision. In particular, the complexity of such polyatomic molecules makes them difficult to control and detect precisely. Employing a more symmetrical measurement procedure can improve the experiment fidelity and alleviate issues associated with molecular complexity. To this end, we theoretically introduce a scheme to perform Ramsey spectroscopy on a racemic mixture of chiral molecules, simultaneously extracting the transition frequencies of the two enantiomers. By taking the difference between the enantiospecific frequencies, we isolate parity violating effects such as the weak force, which is predicted to break the symmetry between enantiomers. To perform the scheme, we design a pulse sequence that creates enantiospecific superpositions in a three-level system using the enantiomer-dependent sign of the electric-dipole moment components’ triple product. A delayed second pulse sequence completes the Ramsey interrogation sequence, enabling readout of the phase evolution for each enantiomer’s transition through a separate quantum state. Our technique overcomes the need to alternate between enantiopure samples to measure parity violation, and is applicable to both charged and neutral molecular species. We describe the advantages of the proposed method for precision metrology.