Single spontaneous photon as a coherent beamsplitter for an atomic matterwave
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.
Cite
@article{arxiv.1012.4704,
title = {Single spontaneous photon as a coherent beamsplitter for an atomic matterwave},
author = {Jiří Tomkovič and Michael Schreiber and Joachim Welte and Martin Kiffner and Jörg Schmiedmayer and Markus K. Oberthaler},
journal= {arXiv preprint arXiv:1012.4704},
year = {2012}
}
Comments
main text: 5 pages, 4 figure; supplementary information: 8 pages, 1 figure