Entanglement generation by communication using phase-squeezed light with photon loss
Fumiaki Matsuoka, Akihisa Tomita, Atsushi Okamoto · Physical Review A · 2016
To implement fault-tolerant quantum computation, entanglement generation with low error probability and high success probability is required. In a previous paper, we proposed the use of squeezed coherent light as a probe to generate entanglement between two atoms by communication and showed that the error probability is reduced well below the threshold of fault-tolerant quantum computation [F. Matsuoka et al., Phys. Rev. A 88, 022313 (2013)]. In this paper, we investigate the effect of photon loss mainly due to finite coupling efficiency to the cavity. The error probability with photon loss is calculated using a beam-splitter model for homodyne measurement of probe light. We examine the optimum conditions of the amplitude of the probe light and the degree of squeezing to minimize the error probability. We show that the phase-squeezed probe light yields lower error probability than a coherent-light probe, even with photon losses. A fault-tolerant quantum computation algorithm can be implemented under 87% transmittance by concatenating a seven-qubit error correction code for the phase-flip error.