Coherent manipulation of a solid-state artificial atom with few photons

• Published in: Nature communications Vol. 7; no. 1; pp. 11986 - 6
• Main Authors: Giesz, V., Somaschi, N., Hornecker, G., Grange, T., Reznychenko, B., De Santis, L., Demory, J., Gomez, C., Sagnes, I., Lemaître, A., Krebs, O., Lanzillotti-Kimura, N. D., Lanco, L., Auffeves, A., Senellart, P.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17-06-2016; Nature Publishing Group; Nature Portfolio
• Subjects: 140/125; 639/624/400/1100; 639/766/36/1121; Atoms & subatomic particles; Electrons; Humanities and Social Sciences; Interfaces; multidisciplinary; Physics; Quantum dots; Quantum Physics; Science; Science (multidisciplinary); France
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11986

In a quantum network based on atoms and photons, a single atom should control the photon state and, reciprocally, a single photon should allow the coherent manipulation of the atom. Both operations require controlling the atom environment and developing efficient atom–photon interfaces, for instance by coupling the natural or artificial atom to cavities. So far, much attention has been drown on manipulating the light field with atomic transitions, recently at the few-photon limit. Here we report on the reciprocal operation and demonstrate the coherent manipulation of an artificial atom by few photons. We study a quantum dot-cavity system with a record cooperativity of 13. Incident photons interact with the atom with probability 0.95, which radiates back in the cavity mode with probability 0.96. Inversion of the atomic transition is achieved for 3.8 photons on average, showing that our artificial atom performs as if fully isolated from the solid-state environment.
Quantum information processing requires a system in which a single photon controls a single atom and
vice versa
. Here, the authors demonstrate such reciprocal operation and achieve coherent manipulation of a quantum dot by a few photons sent on an optical cavity.