Cavity-enhanced single ion quantum optics

Project funded by Swedish Research Council (Project grant), grant 2015-03989_VR. Participating organisations named by the source: Lund University. Funded amount: SEK 3,400,000, as stated by the source. Runs 2016-01-01 to 2019-12-31. Keywords: Naturvetenskap, Natural Sciences, Fysik, Physical Sciences, Atom- och molekylfysik och optik, Atom and Molecular Physics and Optics. Source: OpenAIRE Graph, from the funder's project data (collected by OpenAIRE on 2025-12-05); national funding data, not CORDIS. Abstract given by the source: Quantum enhanced devices show great promise to improve future technology far beyond what is possible today in several fields, such as computing, communication and sensing. The proposed project aims at implementing a quantum switch, operating at the single ion and single photon level, which is a key component for quantum networks, distributed quantum computing and single photon transistors. The quantum switch will consist of a nano crystal doped with neodymium (Nd) ions, placed in a fiber cavity. Nd is a rare earth ion, which was chosen since they are known to have very favorable coherence properties, demonstrated in the past e.g. through quantum memories with both very long lifetimes and high fidelity. Due to the long lifetime however, they are generally difficult to detect at the single ion level, but this can be overcome with the use of an optical cavity. In the present project, the cavity will be made by a shaped and high-reflection coated fiber tip as one of the mirrors. It is designed to have a high finesse (~100 000) and a very small mode volume in the order of a few wavelengths cubed. In this regime, the cavity will affect the vacuum mode density, which in turn will greatly enhance the spontaneous emission of the Nd ion. This will allow a quantum computing protocol based on single rare-earth ions to be efficiently read out. At the same time, in this so called strong coupling regime, there is a back action on the cavity from the single ion, allowing the state of the single Nd ion to switch the reflectivity of the cavity at resonance. This behavior allows single photons to go different paths in a quantum network, based on the state of single ions which can be in quantum superposition states. Both this quantum switching and the enhanced fluorescence readout have the potential to significantly advance the present state of the quantum information processing communication, and the fact that both can be implemented in the same setup demonstrates its versatility and [shortened; the full text is on the OpenAIRE page]

Original source.

Source: OpenAIRE Graph: projects of national funders, OpenAIRE, from the project data of Swedish Research Council. Retrieved 2026-10-28. Licence: Creative Commons Attribution 4.0 (OpenAIRE Graph). Selected metadata, adapted presentation; the publisher's record is authoritative. No endorsement by the source is implied. Licence: Creative Commons Attribution 4.0 (CC BY 4.0).

AI-assisted summary: The project "Cavity-enhanced single ion quantum optics" is funded by the Swedish Research Council with a grant of SEK 3,400,000, running from January 1, 2016, to December 31, 2019, and involves Lund University. It aims to implement a quantum switch using neodymium ions for quantum networks. Suggested technology pillar: enabling. Generated by AI from the public source text; it may contain errors and the original source is authoritative.