[Rayonnement non classique émis par un conducteur cohérent]
Nous rapportons des preuves expérimentales de ce que le champ électromagnétique micro-ondes généré par un conducteur normal, une jonction tunnel placée à ultra-basse température, peut avoir un comportement non classique. Nous démontrons l'existence de compression d'état ainsi que d'enchevêtrement dans cette radiation en mesurant les quadratures du champ électromagnétique à une ou deux fréquences de l'ordre du GHz. Dans une expérience, nous observons que la variance d'une quadrature du bruit photo-assisté généré par la jonction descend sous son niveau de vide. Dans une deuxième expérience, nous démontrons l'existence de corrélations entre les quadratures observées à deux fréquences, corrélations qui peuvent être supérieures à ce qui est permis par la mécanique classique, prouvant que la radiation à ces deux fréquences est enchevêtrée.1
We report experimental evidence that the microwave electromagnetic field generated by a normal conductor, here a tunnel junction placed at ultra-low temperature, can be non-classical. By measuring the quadratures of the electromagnetic field at one or two frequencies in the GHz range, we demonstrate the existence of squeezing as well as entanglement in such radiation. In one experiment, we observe that the variance of one quadrature of the photo-assisted noise generated by the junction goes below its vacuum level. In the second experiment, we demonstrate the existence of correlations between the quadratures taken at two frequencies, which can be stronger than allowed by classical mechanics, proving that the radiation at those two frequencies are entangled.1
Mot clés : Micro-ondes quantiques, Enchevêtrement, Compression d'état, Bruit Quantique, Bruit de grenaille, Jonction tunnel
Jean-Charles Forgues 1 ; Gabriel Gasse 1 ; Christian Lupien 1 ; Bertrand Reulet 1
@article{CRPHYS_2016__17_7_718_0,
author = {Jean-Charles Forgues and Gabriel Gasse and Christian Lupien and Bertrand Reulet},
title = {Non-classical radiation emission by a coherent conductor},
journal = {Comptes Rendus. Physique},
pages = {718--728},
publisher = {Elsevier},
volume = {17},
number = {7},
year = {2016},
doi = {10.1016/j.crhy.2016.07.004},
language = {en},
}
TY - JOUR AU - Jean-Charles Forgues AU - Gabriel Gasse AU - Christian Lupien AU - Bertrand Reulet TI - Non-classical radiation emission by a coherent conductor JO - Comptes Rendus. Physique PY - 2016 SP - 718 EP - 728 VL - 17 IS - 7 PB - Elsevier DO - 10.1016/j.crhy.2016.07.004 LA - en ID - CRPHYS_2016__17_7_718_0 ER -
Jean-Charles Forgues; Gabriel Gasse; Christian Lupien; Bertrand Reulet. Non-classical radiation emission by a coherent conductor. Comptes Rendus. Physique, Volume 17 (2016) no. 7, pp. 718-728. doi : 10.1016/j.crhy.2016.07.004. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2016.07.004/
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