Letter abstract
Nature Physics 4, 915 - 918 (2008)
Published online: 2 November 2008 | doi:10.1038/nphys1110
Subject Categories: Quantum physics | Optical physics | Information theory and computation
Preparation of distilled and purified continuous-variable entangled states
Boris Hage1,
Aiko Samblowski1,
James DiGuglielmo1,
Alexander Franzen1,
Jaromír Fiurá
ek2
&
Roman Schnabel1
The distribution of entangled states of light over long distances is a major challenge in the field of quantum information. Optical losses, phase diffusion and mixing with thermal states lead to decoherence and destroy the non-classical states after some finite transmission-line length. Quantum repeater protocols1, 2, which combine quantum memory3, entanglement distillation4, 5 and entanglement swapping6, were proposed to overcome this problem. Here we report on the experimental demonstration of entanglement distillation in the continuous-variable regime7, 8, 9. Entangled states were first disturbed by random phase fluctuations and then distilled and purified using interference on beam splitters and homodyne detection. Measurements of covariance matrices clearly indicate a regained strength of entanglement and purity of the distilled states. In contrast to previous demonstrations of entanglement distillation in the complementary discrete-variable regime10, 11, our scheme achieved the actual preparation of the distilled states, which might therefore be used to improve the quality of downstream applications such as quantum teleportation12.
- Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik and Leibniz Universität Hannover, Callinstr. 38, 30167 Hannover, Germany
- Department of Optics, Palacký University, 17. listopadu 50, 77200 Olomouc, Czech Republic
Correspondence to: Roman Schnabel1 e-mail: roman.schnabel@aei.mpg.de
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Entanglement distillation Pick the best and ignore the restNature Physics News and Views (01 Dec 2008)
Quantum information Flight of the qubitNature News and Views (11 Mar 2004)
RESEARCH
Two independent experiments demonstrate that quantum entanglement that has been lost in decoherence processes can be recovered. For the first time such ?entanglement distillation? has been achieved for states of light that are entangled in continuous variables, which should help to increase the distance over which quantum information can be distributed. Two independent experiments demonstrate that quantum entanglement that has been lost in decoherence processes can be recovered. For the first time such ?entanglement distillation? has been achieved for states of light that are entangled in continuous variables, which should help to increase the distance over which quantum information can be distributed. Measured Gaussian LN before and after distillation and the corresponding success rates.Nature Physics Letter (01 Dec 2008)
Supplementary InformationNature Physics Letter (01 Aug 2009)
See all 38 matches for Research
