Orbital angular momentum photon states from superconductor-semiconductor light sources

• Applicant: Professor Dr. Sven Höfling
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 561114323

The project aims to develop an innovative superconducting light-emitting diode (SLED) by combining superconductors and semiconductors in a unique structure. A key feature of this SLED is the generation of photon pairs entangled in their orbital angular momentum (OAM), a quantum property of light that can carry quantum information. The project will explore how superconducting materials, with their distinct quantum properties, can be effectively integrated into photonic devices, advancing fundamental understanding in both fields. The main objectives include designing a new SLED structure with superconducting contacts on both sides of a pn semiconductor junction. This configuration aims to enhance the quality of coincident photon pair emission, reducing noise and increasing purity, both essential for reliable photon-based quantum experiments. Another goal is to demonstrate the controlled emission of photon pairs with specific OAM states. These “twisted” photons will enable new ways to encode quantum information, providing a platform to study quantum entanglement and coherence effects in superconducting-semiconductor systems. The project will also investigate coupling mechanisms between superconducting qubits and photonic states in the SLED. This exploration could allow superconducting quantum states to be mapped onto photons, offering a new experimental method to study coherent quantum interactions and potentially link solid-state quantum systems with photonic qubits. To further improve emission characteristics, the addition of circular Bragg gratings will enhance photon yield and emission efficiency, allowing for more precise control over the spatial structure and emission direction of the photons. In summary, this project aims to create a hybrid quantum system combining superconducting and photonic components, merging their unique properties in a single device. By expanding our understanding of quantum interactions between superconducting and photon-based quantum states, this research could pave the way for new experimental techniques in quantum optics and facilitate the integration of superconducting quantum systems with optical quantum technologies.

• DFG Programme: Research Grants
• International Connection: Israel
• Partner Organisation: The Israel Science Foundation
• Cooperation Partner: Professor Dr. Alex Hayat