Towards trapped-ion qudit measurement in ¹³⁷Ba⁺ by quadrupole shelving

We present on initial results of trapped-ion qudit shelving measurements using the quadrupole transition in barium ions. We describe shelving sequences which will allow for optimal measurement of up to 5-level qudits using adiabatic passage, and we estimate this protocol to have a fidelity of over 99% for up to 5-level qudits. This work is a first-step towards fully implementing the qudit framework of quantum-information processing in trapped-ion systems. We also observed useful four-level dynamics which allowed us to coarsely tune the 1 Hz laser to the quadrupole transition before fine-tuning by Rabi oscillations. We present progress on spectroscopy of the quadrupole transition and other experimental steps towards full qudit manipulation.