UCLA

Ytterbium is a popular species both for quantum information and precision measurement. 171Yb+ specifically has a long history of use in quantum computing due to the simplicity of state preparation and long coherence times present in spin-1/2 isotopes. In addition, the species’ use in atomic clocks due to their narrow 435 nm and 411 nm resonances have gained prominence. In this thesis, we explore several techniques to improve quantum computation primitives in 171Yb+, and we demonstrate the first trapping of 173Yb+.

We first demonstrate a shelving technique that utilizes the metastable 2F7/2 manifold as a place to ”shelve” quantum information, enabling us to surpass the conventional limits on state preparation and measurement (SPAM) fidelity and greatly increase our state detection duration. Using the narrow 411 nm transition to the 2D5/2 state, we optically pump into themetastable manifold without the need to directly drive the E3 transition. We demonstrate a SPAM inaccuracy of 1.5(10)×10−4. The final inaccuracy is limited by a previously unobserved M1 decay, which we were able to quench to demonstrate a further reduction in the SPAM error. Finally, we demonstrate the potential of the 2F7/2 state as a qubit, demonstrating high-fidelity heralded SPAM and single-qubit gates.

Next, we explore an effect in which the magnetic field-induced state mixing in the ground state hyperfine clock qubit in 171Yb+ introduces polarization dependence. With a given choice of magnetic field, this state mixing allows one to tune the polarization of perturbing light to a ”magic polarization” such that differential light shift of the qubit is eliminated. We demonstrate this effect in ytterbium, and show an improvement in the coherence of the qubit by a factor of 2000.

Finally, we discuss the trapping, cooling, and spectroscopy of a previously untrapped isotope: 173Yb+, with the ultimate aim of examining the hyperfine structure of the 2F7/2 state as a sensitive probe of the isotope’s nuclear structure. We measure the hyperfine structure coefficients of the following previously unmeasured 2D3/2, 2D5/2, 3[3/2]1/2, and 1[3/2]3/2 states, laying the groundwork for hyperfine Ramsey spectroscopy of the 2F7/2 state.We then discuss potential future applications of 173Yb+ in quantum information and precision measurement.