Identification of molecular quantum states using phase-sensitive forces

Abstract

Quantum-logic techniques used to manipulate quantum systems are now increasingly being applied to molecules. Previous experiments on single trapped diatomic species have enabled state detection with excellent fidelities and highly precise spectroscopic measurements. However, for complex molecules with a dense energy-level structure improved methods are necessary. Here, we demonstrate an enhanced quantum protocol for molecular state detection using state-dependent forces. Our approach is based on interfering a reference and a signal force applied to a single atomic and molecular ion, respectively, in order to extract their relative phase. We use this phase information to identify states embedded in a dense molecular energy-level structure and to monitor state-to-state inelastic scattering processes. This method can also be used to exclude a large number of states in a single measurement when the initial state preparation is imperfect and information on the molecular properties is incomplete. While the present experiments focus on N${}_2^{+}$, the method is general and is expected to be of particular benefit for polyatomic systems.

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Cited by in corpus (3)

• Quantum-Logic Detection of Chemical Reactions
• From megahertz to terahertz qubits encoded in molecular ions: theoretical analysis of dipole-forbidden spectroscopic transitions in N${}_2^{+}$
• Unresolved sideband photon recoil spectroscopy of molecular ions