Optical control of the refractive index of a single atom

T. Kampschulte, W. Alt, S. Brakhane, M. Eckstein, R. Reimann, A. Widera, D. Meschede

Phys. Rev. Lett. 105 153603 (2010)

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Abstract

We experimentally demonstrate the elementary case of electromagnetically induced transparency with a single atom inside an optical cavity probed by a weak field. We observe the modification of the dispersive and absorptive properties of the atom by changing the frequency of a control light field. Moreover, a strong cooling effect has been observed at two-photon resonance, increasing the storage time of our atoms twenty-fold to about 16 seconds. Our result points towards all-optical switching with single photons.