Integrated optical addressing of an ion qubit

Area of Science:

• Quantum Information Science
• Atomic Physics
• Nanophotonics

Background:

• Trapped ion qubits offer long coherence times and high-fidelity operations, crucial for quantum information processing.
• Current optical systems for addressing individual ions are complex and hinder scalability beyond a few tens of qubits.

Purpose of the Study:

• To demonstrate a scalable method for light delivery and ion addressing in trapped ion systems.
• To integrate nanophotonic waveguide devices directly onto a surface-electrode ion trap chip.

Main Methods:

• Fabrication of lithographically defined nanophotonic waveguide devices integrated into a surface-electrode ion trap.
• Utilizing focusing grating couplers to deliver light to ions trapped 50 μm above the chip.
• Performing quantum coherent operations on the optical qubit transition of individual 88Sr+ ions.

Main Results:

• Demonstrated precise light delivery and addressing of individual trapped ions using integrated nanophotonics.
• Achieved quantum coherent operations with measured crosstalk errors between 10^-2 and 4x10^-4.
• The nanophotonic approach offers scalability and stable alignment for trapped ion systems.

Conclusions:

• Integrated nanophotonic waveguides provide a scalable solution for optical control in trapped ion quantum processors.
• This technology overcomes limitations of traditional optical setups, paving the way for large-scale quantum information processing.