Rare-earth-based single photon sources for quantum telecommunication compatible with spin quantum memories

• Applicant: Dr. Roman Kolesov
• Subject Area: Experimental Condensed Matter Physics ; Synthesis and Properties of Functional Materials ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 379110753

The project is aiming at creating single photon sources in the telecom wavelength range on the basis of single rare-earth emitters, in particular, erbium, doped into optical crystals. The crucial advantages of the proposed single photon sources are true single photon emission, transform limited linewidth, and a possibility of direct storage of the emitted photons in a rare-earth-based optical memory. The latter is highly desirable for quantum repeater operation. The proposal is based on enhancing optical emission of rare-earth ions by cavity QED effects. Even though the brigtness of erbium ions is low, it can be boosted up by several orders of magnitude once the ions are coupled to high quality optical resonator. The latter is proposed to be manufactured out of the high quality thin titanium dioxide or lithium niobate film deposited on top of the optical crystal. In turn, the coupling between the emitter and the cavity is due to evanescent tail of the cavity mode leaking into the substrate crystal. The performance of the single photon source will be assessed by measuring its brightness and indistinguishability of the emitted photons in a Hong-Ou-Mandel experiment. Once the project is successful, it will result in a versatile method of creation of scalable on-chip single photon sources compatible with state of the art quantum memories for quantum telecommunication.

• DFG Programme: Research Grants
• Major Instrumentation: Two-channel superconducting infrared detector
• Instrumentation Group: 5800 Photodetektoren, -zellen, -widerstände für UV-VIS