Concatenate Codes and Space Optimization for Fault-Tolerant Quantum Computation

Learn about fault-tolerant quantum computation protocols through this conference talk that introduces a groundbreaking approach using concatenated codes instead of quantum LDPC codes. Explore how this new protocol achieves significant improvements in space overhead reduction, reaching over 90% for logical CNOT error rates of 10^-10 and 97% for 10^-24 compared to surface code protocols. Discover the protocol's impressive 2.4% threshold under circuit-level error modeling, surpassing surface code performance. Understand how the concatenated code approach naturally creates abstraction layers crucial for modular FTQC architectures while maintaining a balance between critical factors like space overhead, threshold, and modularity. Presented at the 19th Theory of Quantum Computation, Communication and Cryptography Conference (TQC 2024) at OIST, Japan, this talk demonstrates how code concatenation techniques can significantly optimize qubit usage in practical fault-tolerant quantum computation implementations.