Fault-tolerant measurement-based quantum computing with continuous-variable cluster states

Phys Rev Lett. 2014 Mar 28;112(12):120504. doi: 10.1103/PhysRevLett.112.120504. Epub 2014 Mar 26.


A long-standing open question about Gaussian continuous-variable cluster states is whether they enable fault-tolerant measurement-based quantum computation. The answer is yes. Initial squeezing in the cluster above a threshold value of 20.5 dB ensures that errors from finite squeezing acting on encoded qubits are below the fault-tolerance threshold of known qubit-based error-correcting codes. By concatenating with one of these codes and using ancilla-based error correction, fault-tolerant measurement-based quantum computation of theoretically indefinite length is possible with finitely squeezed cluster states.