Transport of Multispecies Ion Crystals through a Junction in a Radio-Frequency Paul Trap
William Cody Burton, Brian Estey, Ian M. Hoffman, Abigail R. Perry, Curtis Volin, Gabriel Price
Abstract
We report on the first demonstration of transport of a multispecies ion crystal through a junction in a rf Paul trap. The trap is a two-dimensional surface-electrode trap with an $\mathsf{X}$ junction and segmented control electrodes to which time-varying voltages are applied to control the shape and position of potential wells above the trap surface. We transport either a single ${^{171}\mathrm{Yb}}^{+}$ ion or a crystal composed of a ${^{138}\mathrm{Ba}}^{+}$ ion cotrapped with the ${^{171}\mathrm{Yb}}^{+}$ ion to any port of the junction. We characterize the motional excitation by performing multiple round-trips through the junction and back to the initial well position without cooling. The final excitation is then measured using sideband asymmetry. For a single ${^{171}\mathrm{Yb}}^{+}$ ion, transport with a $4\text{ }\text{ }\mathrm{m}/\mathrm{s}$ average speed induces between $0.013\ifmmode\pm\else\textpm\fi{}0.001$ and $0.014\ifmmode\pm\else\textpm\fi{}0.001$ quanta of excitation per round-trip, depending on the exit port. For a Ba-Yb crystal, transport at the same speed induces between $0.013\ifmmode\pm\else\textpm\fi{}0.001$ and $0.030\ifmmode\pm\else\textpm\fi{}0.002$ quanta per round-trip of excitation to the in-phase axial mode. Excitation in the out-of-phase axial mode ranges from $0.005\ifmmode\pm\else\textpm\fi{}0.001$ to $0.021\ifmmode\pm\else\textpm\fi{}0.001$ quanta per round-trip.