Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 43: Poster II

Q 43.84: Poster

Wednesday, March 20, 2013, 16:00–18:30, Empore Lichthof

Four-wave mixing’s effect on EIT propagation: spontaneous emission and vacuum noise — •Christopher O’Brien, Nikolai Lauk, and Michael Fleischhauer — Fachbereich Physik, Technische Universität Kaiserslautern

In electromagnetically induced transparency (EIT), a propagating signal field resonant with an optical transition is coupled in a Λ scheme by a strong resonant laser driving an adjacent transition, quantum interference then makes the medium transparent to the signal. In many EIT experiments, the driving laser also acts as a far-detuned field on the signal transition, which for high optical depth causes a four-wave mixing (FWM) process. The far-detuned field generates a new co-propagating idler field which along with the driving field moves population into the excited state, giving gain for the signal field. The presence of gain introduces noise on the signal field, due to both spontaneous emission as well as a vacuum contribution of the idler. To find analytic expressions for the noise, we solve the Maxwell-Bloch equations for the propagating field operator in a EIT FWM medium. We can then discuss the effect of FWM on EIT experiments, such as those done for EIT based quantum memories.