Topological quantum computing with a very noisy network and local error rates approaching one percent

Area of Science:

• Quantum computing
• Quantum information science
• Error correction codes

Background:

• Scalable quantum computers may be built by networking simple processor cells.
• Realistic quantum networks are prone to errors, hindering scalability.
• Previous purification methods required prohibitively low internal cell error rates.

Purpose of the Study:

• To present a novel method for error purification in networked quantum systems.
• To enable the use of error-prone quantum cells for scalable quantum computation.

Main Methods:

• Groups of quantum cells generate shared resource states.
• These shared states stabilize topologically encoded data.
• The protocol operates on a realistically noisy network with error rates of 10% or higher.

Main Results:

• The proposed purification method succeeds even with error-prone cells.
• Success is achieved if intra-cell error rates for initialization, manipulation, and measurement are below 0.82%.
• This fidelity threshold is attainable in current laboratory quantum systems.

Conclusions:

• The developed protocol overcomes limitations of previous purification techniques.
• It offers a viable pathway for building scalable quantum computers using imperfect components.
• This research advances the practical realization of fault-tolerant quantum computation.