Control and readout of a superconducting qubit using a photonic link

Area of Science:

• Quantum computing
• Superconducting quantum information processing
• Cryogenic engineering

Background:

• Universal quantum computers require millions of qubits.
• Current superconducting processors are limited to a few thousand qubits due to complex wiring and heat load.
• Existing methods involve multiple coaxial lines per qubit, hindering scalability.

Purpose of the Study:

• To introduce a novel photonic link for delivering microwave signals to superconducting qubits.
• To demonstrate the feasibility of using optical fibers for quantum information processing.
• To overcome the scalability limitations of current quantum computing architectures.

Main Methods:

• Utilizing an optical fiber to guide modulated laser light from room temperature to a cryogenic photodetector.
• Employing a photonic link to deliver shot-noise-limited microwave signals at millikelvin temperatures.
• Integrating the photonic link with superconducting quantum processors for qubit control and readout.

Main Results:

• High-fidelity control and readout of a superconducting qubit were achieved using the photonic link.
• The photonic link meets the stringent requirements for superconducting quantum information processing.
• Demonstrated efficient and massively multiplexed delivery of coherent microwave control pulses.

Conclusions:

• The developed photonic link provides a scalable solution for controlling and reading out superconducting qubits.
• This technology offers a viable path towards building universal quantum computers with millions of qubits.
• Optical fiber-based interconnects are crucial for advancing large-scale quantum information processing.