Metastable Qubit in $^{171}$Yb$^{+}$

Metastable qubits in trapped ion arrays offer an alternative to multi-species traps by preserving the advantage of qubit indistinguishability, and by reducing the challenge associated with adding an additional species to a trapped ion experiment. We have shown that the ground state ($^{2}$S$_{1/2}$) hyperfine qubit in $^{171}$Yb$^{+}$ has excellent state preparation and measurement (SPAM) fidelity (F$\geq$0.999), and is thus a good candidate for trapped ion quantum computation. Additionally, the $^{2}$F$_{7/2}$ state is ideally suited to host a metastable qubit due to its approximately 5 year lifetime and its large optical frequency separation from the transitions used in the $^{2}$S$_{1/2}$ qubit operations. We perform single-qubit gates and measure the $^{2}$F$_{7/2}$ clock-state qubit SPAM fidelity of this metatable qubit as F$\geq$0.95. By coherently mapping the population between the $^{2}$S$_{1/2}$ (“operational”) and $^{2}$F$_{7/2}$ (“storage”) qubits through an electric octupole transition, one may perform operations on a set of qubits while others are unaffected. In combination with coherent mapping, the ability to use metastable qubits in a multi-qubit array provides promising schemes for the implementation of gate operations.