Nature456, 773-777 (11 December 2008) | doi:10.1038/nature07607; Received 27 June 2008; Accepted 30 October 2008
A solid-state light–matter interface at the single-photon level
Hugues de Riedmatten1,2, Mikael Afzelius1,2, Matthias U. Staudt1, Christoph Simon1 & Nicolas Gisin1
Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland
These authors contributed equally to this work.
Correspondence to: Hugues de Riedmatten1,2 Correspondence and requests for materials should be addressed to H.d.R. (Email: hugues.deriedmatten@unige.ch).
Coherent and reversible mapping of quantum information between light and matter is an important experimental challenge in quantum information science. In particular, it is an essential requirement for the implementation of quantum networks and quantum repeaters1, 2, 3. So far, quantum interfaces between light and atoms have been demonstrated with atomic gases4, 5, 6, 7, 8, 9, and with single trapped atoms in cavities10. Here we demonstrate the coherent and reversible mapping of a light field with less than one photon per pulse onto an ensemble of 107 atoms naturally trapped in a solid. This is achieved by coherently absorbing the light field in a suitably prepared solid-state atomic medium11. The state of the light is mapped onto collective atomic excitations at an optical transition and stored for a pre-determined time of up to 1 s before being released in a well-defined spatio-temporal mode as a result of a collective interference. The coherence of the process is verified by performing an interference experiment with two stored weak pulses with a variable phase relation. Visibilities of more than 95 per cent are obtained, demonstrating the high coherence of the mapping process at the single-photon level. In addition, we show experimentally that our interface makes it possible to store and retrieve light fields in multiple temporal modes. Our results open the way to multimode solid-state quantum memories as a promising alternative to atomic gases.
107 atoms naturally trapped in a solid. This is achieved by coherently absorbing the light field in a suitably prepared solid-state atomic medium
s before being released in a well-defined spatio-temporal mode as a result of a collective interference. The coherence of the process is verified by performing an interference experiment with two stored weak pulses with a variable phase relation. Visibilities of more than 95 per cent are obtained, demonstrating the high coherence of the mapping process at the single-photon level. In addition, we show experimentally that our interface makes it possible to store and retrieve light fields in multiple temporal modes. Our results open the way to multimode solid-state quantum memories as a promising alternative to atomic gases.
