Programmable four-photon graph states on a silicon chip

Area of Science:

• Quantum computing
• Photonics
• Quantum information science

Background:

• Scalable architectures are crucial for future quantum computers.
• Measurement-based protocols using graph states are state-of-the-art for optical quantum computing.
• Silicon photonics offers a scalable technology with proven quantum optical functionality.

Purpose of the Study:

• To produce and encode photonic graph states on a mass-manufactured silicon chip.
• To demonstrate programmability in generating four-photon graph states.
• To implement and test a basic measurement-based protocol using on-chip generated photons.

Main Methods:

• Generating four photons on-chip using silicon photonics.
• Programmably generating all types of four-photon graph states.
• Implementing a measurement-based protocol and measuring heralded interference.
• Developing a device model and using Bayesian inference to bound error sources.

Main Results:

• Successful production and encoding of photonic graph states on a mass-manufactured chip.
• Programmable generation of all four-photon graph state types.
• High-visibility heralded interference measured from the chip's four photons.
• Dominant error sources bounded using Bayesian inference.

Conclusions:

• The combination of measurement-based quantum computation, silicon photonics, and on-chip multi-pair sources is promising for scalable quantum information processing.
• This work represents a significant step towards building large-scale photonic quantum computers.
• The developed methods pave the way for future advancements in quantum technologies.