Abstract
We demonstrate a heralded quantum memory where a photon announces the mapping of a light polarization state onto a single collective-spin excitation (magnon) shared between two atomic ensembles. The magnon can be converted at a later time into a single polarized photon with polarization fidelity over 90(2)% for all fiducial input states, well above the classical limit of . The process can be viewed as a nondestructive quantum probe where a photon is detected, stored, and regenerated without touching its—potentially undetermined—polarization.
- Received 26 August 2008
DOI:https://doi.org/10.1103/PhysRevLett.103.043601
©2009 American Physical Society
Viewpoint
Heralding the storage of light
Published 20 July 2009
This design of atomic quantum memory tells us when a pulse of light has been successfully stored and then proceeds to retrieve it without significantly affecting its polarization. The exquisite operation provides a new capability for quantum information networks.
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