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arXiv · 1012.4704

Single spontaneous photon as a coherent beamsplitter for an atomic matterwave

Jiří Tomkovič·Michael Schreiber·Joachim Welte·Martin Kiffner·Jörg Schmiedmayer·Markus K. Oberthaler
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Abstract

In spontaneous emission an atom in an excited state undergoes a transition to the ground state and emits a single photon. Associated with the emission is a change of the atomic momentum due to photon recoil. Photon emission can be modified close to surfaces and in cavities. For an ion, localized in front of a mirror, coherence of the emitted resonance fluorescence has been reported. In free space experiments demonstrated that spontaneous emission destroys motional coherence. Here we report on motional coherence created by a single spontaneous emission event close to a mirror surface. The coherence in the free atomic motion is verified by atom interferometry. The photon can be regarded as a beamsplitter for an atomic matterwave and consequently our experiment extends the original recoiling slit Gedanken experiment by Einstein to the case where the slit is in a robust coherent superposition of the two recoils associated with the two paths of the quanta.

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Jiří Tomkovič, Michael Schreiber, Joachim Welte, Martin Kiffner, Jörg Schmiedmayer, Markus K. Oberthaler. 2012-09-27. Single spontaneous photon as a coherent beamsplitter for an atomic matterwave. https://doi.org/10.1038/nphys1961

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