Quantum dot micro-cavity solid-state quantum light sources

• Applicant: Professor Dr. Christian Schneider
• Subject Area: Experimental Condensed Matter Physics ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 338972874

This project focuses on the realization and application of a solid-state microcavity quantum dot system for quantum communication and information processing. It has as a target the development of tools needed achieve unprecedentedly efficient sources of quantum states of light. The envisioned platform consists of quantum dots embedded in an engineered microcavity structures. This approach will allow for quantum light source qualities not easily achievable in the existing systems.In particular we aim at design, fabrication, and characterization in resonant excitation, of two types of photonic devices. The first device will consist of a single quantum dot that is deterministically embedded in a pillar microcavity specifically designed to enhance emission of linearly polarized single photons. This enhancement will be achieved by implementation of an asymmetric pillar microcavity. The microcavity design will be adapted in such a way, to maximize the coherence of the emitted photons as well as collection efficiency. Our second device will address the problem of Purcell enhancement in broadband photonic structures. Such an implementation is strongly required for efficient collection of pairs of photons emitted by a single quantum dot. In addition, a moderate Purcell enhancement allows for collection of photons with very high coherence of the wavepacket. This will be achieved by implementation of microcavities with a tapered pillar.The implemented devices will be tested by state-of-the-art resonant laser spectroscopy including two-photon excitation techniques to deterministically create biexcitonic states in the emitter. This approach will allow for experiments such as very efficient generation of time-bin entangled photons with very high degree of entanglement and time multiplexed multi-photon entangled states. Our experiments will ultimately test the capability of the microcavity collection enhancement approach to make quantum light sources suitable for future on- or off- chip quantum networks and photonic quantum emulators.

• DFG Programme: Research Grants
• Ehemalige Antragstellerin: Professorin Ana Predojevic, Ph.D., until 8/2017