Newly-observed narrow transitions in Yb⁺ for quantum information processing and precision measurement

The metastable ("m-type") qubit defined on zero-field hyperfine clock states in the long-lived ²F_7/2 manifold in Yb⁺ gives a promising pathway to low cross-talk, high fidelity multi-qubit operations using the same ion species via the recently proposed "omg blueprint'' for atomic quantum processing. The m-type qubit has been shown to have excellent initialization and readout fidelity when paired with heralded state preparation, but coupling these states to motion is not straightforward using conventional techniques. The structure of further-excited Yb⁺ contains many odd-parity, metastable states that are accessible directly from the ²F_7/2 manifold, furnishing new optical-frequency ("o-type") qubit capabilities. We report isotope shifts and lifetimes for three near-infrared and visible E2 transitions from the ²F_7/2 manifold to higher metastable states and measurements of their hyperfine structure. These narrow transitions can form the basis for engineering a state-dependent force for the m-type qubit. The addition of these previously unobserved transitions to Yb⁺ at accessible wavelengths may aide in the search for isotope shift nonlinearities.