Stuttgart 2012 – wissenschaftliches Programm
Q 35.75: Poster
Mittwoch, 14. März 2012, 16:30–19:00, Poster.I+II
Narrowband Source of Correlated Photon Pairs via Four-Wave Mixing in Atomic Vapour — Bharath Srivathsan1, Gurpreet Kaur Gulati1, Mei Yuen Brenda Chng1, Gleb Maslennikov1, Dzmitry Matsukevich1,2, and •Christian Kurtsiefer1,2 — 1Centre for Quantum Technologies, National University of Singapore, Singapore 117543 — 2Department of Physics, National University of Singapore, Singapore 117542
Many quantum communication protocols require entangled states of distant qubits which can be implemented using photons. To efficently transfer entanglement from photons to stationary qubits such as atoms, one requires entangled photons with a frequency bandwidth matching the absorption profile of the atoms. In our setup, a cold Rb87 atomic ensemble is pumped by two laser beams (780nm and 776nm) resonant with the 5S1/2→ 5P3/2 → 5D3/2 transition. This generates time-correlated photon pairs (776nm and 795nm) by nondegenerate four-wave mixing via the decay path 5D3/2→ 5P1/2 → 5S1/2. Coupling the photon pairs into single mode fibres and using silicon APDs, we observe g(2) of about 2000 and pairs to singles ratio of 11.2% (2800 photon pairs per second) with an optical bandwidth < 30/(2π) MHz.
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