Entangled Photons from a Single Molecule, for Experiments on Single Emitters, Quantum Memories and Atomic Gases

• Applicant: Professor Dr. Ilja Gerhardt
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Experimental Condensed Matter Physics
• Term: since 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 328407404

This proposal aims to enable a novel source of photonic entanglement. The purposed source will address two main drawbacks of the presently available sources: a) the limitation to nearinfrared optical photons and b) the missing spectral superposition and alignment to an atomic quantum memory. Both features can be fulfilled by using single photons originating from a single emitter, and entangling them subsequently by an all-optical gate. Although both parts of the suggested implementation were realized before, their combination poses many challenges to the experimentalists. The final implementation will allow an optical interaction of the generated photons with atomic vapors, which can implement a quantum memory. Or, alternatively, an optical interaction among several single emitters. We believe, that our novel resource of photonic entanglement allows to be in terms of spectral brightness and flux superior, or at least equivalent, to the existing sources, which are all reviewed in the proposal. The extension to spectral degenerateentanglement in the blue part of the spectrum, extends the range of usable quantum memories and stationary qubits for future applications, such as quantum repeaters.

• DFG Programme: Research Grants