Progress Towards a Multispecies Ion System for Remote and Local Entanglement Generation

Entanglement within and across remote trapped ion quantum registers has been previously demonstrated with $^{171}$Yb$^+$. In order to generate remote entanglement, a pulsed laser excites an ion in each register and the spontaneously emitted photons are collected. However, there is a similar probability that uncollected photons will scatter from adjacent ions, resulting in the loss of locally stored quantum information. To address this issue, we are implementing a multispecies system in which Yb$^+$ acts as a quantum memory and Ba$^+$ provides a photonic interlink. Not only does this minimize disruption of the Yb$^+$ quantum memory qubits, but photons from both the 493 nm and 650 nm transition in Ba$^+$ are more easily converted to telecom wavelengths. We report progress on such a system which requires co-trapping of these species, quantum logic spectroscopy for state detection, and the implementation of a multi-species phase gate utilizing a single pulsed laser.