Compact, Cryogenic Surface-Electrode Penning Trap for Quantum Information Experiments

Penning ion traps are ideal platforms for precision measurement and quantum simulation experiments with single trapped atomic ions or two-dimensional crystals. Recently, researchers have demonstrated trapping, transport, and electric field mapping in Penning traps constructed using microfabricated two-dimensional electrode arrays [i.e. surface-electrode Penning traps (SEPTs]. These novel surface traps provide the necessary components for implementation of QCCD operations. These SEPTs provide long trap lifetime, low ion heating rates, and no radiofrequency micromotion – featuring only DC electrodes along with an externally-applied, uniform, static magnetic field for confinement. The Tesla-scale magnetic fields of Penning traps also allow for novel qubit encodings (e.g. omg), exquisite spectral resolution of atomic transitions (relaxed polarization requirements), and stable motional frequencies (e.g. ppm). We report progress towards implementation of a permanent-magnet-based SEPT operating at cryogenic temperatures. We also detail experimental results using ⁴⁰Ca⁺ optical, metastable, and ground state qubits in our existing room-temperature compact Penning trap including: sub-Doppler cooling of axial and radial modes of a single ion, state preparation and measurement, high-fidelity one-qubit metastable operations, and entanglement of spin and axial motion.