Hannover 2013 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 54: Quantum information: Photons and nonclassical light I

Q 54.7: Vortrag

Donnerstag, 21. März 2013, 15:45–16:00, E 001

Quantum noise for Faraday light-matter interfaces — •Denis Vasilyev and Klemens Hammerer — Leibniz University Hanover, 30167 Hanover, Germany

In light-matter interfaces based on the Faraday effect, quite a number of quantum information protocols have been successfully demonstrated. In order to further increase the performance and fidelities achieved in these protocols, a deeper understanding of the relevant noise and decoherence processes needs to be gained. In this paper, we provide for the first time a complete description of the decoherence from spontaneous emission. We derive from first principles the effects of photons being spontaneously emitted into unobserved modes. Our results relate the resulting decay and noise terms in effective equations of motion for collective atomic spins and the forward-propagating light modes to the full atomic level structure. We illustrate and apply our results to the case of a quantum memory protocol. Our results can be applied to any alkali atoms, and the general approach taken in this paper can be applied to light-matter interfaces and quantum memories based on different mechanisms.