Individual-Ion Addressing and Readout in a Penning Trap

Area of Science:

• Quantum Information Science
• Atomic, Molecular, and Optical Physics
• Quantum Simulation

Background:

• Trapped ions are a leading platform for quantum computing and simulation.
• Individual addressing and readout are crucial for scalable quantum operations.
• Previous methods faced challenges in scalability and precision.

Purpose of the Study:

• To implement individual addressing and readout of ions in a rotating planar crystal.
• To demonstrate qubit operations using a metastable manifold and focused laser beams.
• To assess the fidelity of addressing operations and identify limitations.

Main Methods:

• Utilizing a compact Penning trap with a rotating triangular potential to stabilize a ^{40}Ca^{+} crystal.
• Implementing parallel readout in the rotating frame via detected ion fluorescence.
• Encoding qubits in the metastable D_{5/2} manifold for near-infrared laser operations.
• Employing a focused ac Stark shifting laser for addressed σ_{z} operations.

Main Results:

• Successfully demonstrated individual ion addressing and readout across the crystal.
• Achieved addressed σ_{z} operations on ions at various radial positions.
• Simulations indicate current addressing fidelity of ~97%, limited by thermal effects.
• Identified potential for fidelity improvement to <10^{-3} with sub-Doppler cooling.

Conclusions:

• The demonstrated techniques provide a complete set of operations for quantum simulation on this platform.
• This work advances the development of scalable and high-fidelity trapped-ion quantum processors.
• The compact design and demonstrated control are promising for future quantum technologies.