Second-Scale ${}^9{\text{Be}}^{+}$ Spin Coherence in a Compact Penning Trap

Brian J. McMahon, Brian C. Sawyer

We report microwave spectroscopy of co-trapped ${}^9{\text{Be}}^{+}$ and ${}^{40}{\text{Ca}}^{+}$ within a compact permanent-magnet-based Penning ion trap. The trap is constructed with a recon…