Quantum communications with compressed decoherence using bright squeezed light

Abstract

We propose a scheme for long-distance distribution of quantum entanglement in which the entanglement between qubits at intermediate stations of the channel is established by using bright light pulses in squeezed states coupled to the qubits in cavities with a weak dispersive interaction. The fidelity of the entanglement between qubits at the neighbor stations (10 km apart from each other) obtained by postselection through the balanced homodyne detection of 7 dB squeezed pulses can reach F = 0.99 without using entanglement purification, at the same time, the probability of successful generation of entanglement is 0.34.

Keywords:

• squeezed state
• quantum communication
• homodyne detection

Acknowledgements

This work was supported by the State Key Programs for Basic Research of China (2005CB623605 and 2006CB921803), and by National Foundation of Natural Science in China Grant Nos. 10474033 and 60676056.