Fusion-based quantum computation.

Area of Science:

• Quantum Computing
• Photonics
• Quantum Error Correction

Background:

• Standard quantum computing relies on deterministic unitary entangling gates, which are challenging to implement in photonic systems.
• Photonic systems offer natural primitives like entangling measurements (fusions) that can be leveraged for computation.

Purpose of the Study:

• To introduce fusion-based quantum computation, a model tailored for fault-tolerant quantum computing using readily available photonic primitives.
• To demonstrate that this model can achieve a higher error threshold compared to existing schemes.

Main Methods:

• Utilizing entangling measurements (fusions) on qubits within small, constant-sized entangled resource states.
• Integrating probabilistic photonic gates and errors directly into a quantum error correction protocol.
• Developing a ballistic scheme to manage photon loss during fusion operations.

Main Results:

• The fusion-based model achieves a higher fault-tolerance threshold than previously reported schemes.
• The proposed ballistic scheme tolerates a 10.4% photon loss probability per fusion (2.7% per photon).
• The architecture is highly modular with reduced classical processing demands.

Conclusions:

• Fusion-based quantum computation provides a viable and robust model for fault-tolerant quantum computing in photonic systems.
• This approach effectively handles probabilistic gates and photon loss through integrated error correction.
• The modularity and efficiency offer significant advantages over prior photonic quantum computing architectures.