Topological Cluster State Computation with Photons
Simon J. Devitt, Austin G. Fowler, Ashley M. Stephens, Andrew D. Greentree, Lloyd C. L. Hollenberg, William J. Munro, Kae Nemoto · arXiv (Cornell University) · 2008
Entanglement is one of the most mysterious and fleeting properties of nature. It is also a powerful resource for quantum information processing. Efforts to design and build a quantum computer are severely constrained by the difficulties of preserving useful qubit entanglement against the environment. Concatenated fault-tolerant error correction provides a framework to perform scalable computation, but is extremely expensive in terms of resources. Direct topological implementations promise robust entanglement and control, but require physical systems with as yet unobserved controllable topological phases. Here we present the first practical scheme for constructing a topological quantum computer based on a 3D cluster state lattice of photons on chip. In contrast to the resource requirements of other schemes, a target error rate of 10^(-16) requires approximately 3000 components per logical qubit. This constitutes a significant advance towards practical quantum computing and leads the way for topological architectures in other implementations.