Fault-tolerant linear optical quantum computing with small-amplitude coherent States

Phys Rev Lett. 2008 Jan 25;100(3):030503. doi: 10.1103/PhysRevLett.100.030503. Epub 2008 Jan 25.

Abstract

Quantum computing using two coherent states as a qubit basis is a proposed alternative architecture with lower overheads but has been questioned as a practical way of performing quantum computing due to the fragility of diagonal states with large coherent amplitudes. We show that using error correction only small amplitudes (alpha>1.2) are required for fault-tolerant quantum computing. We study fault tolerance under the effects of small amplitudes and loss using a Monte Carlo simulation. The first encoding level resources are orders of magnitude lower than the best single photon scheme.