Periodic Reporting for period 1 - SuperPHOTON (2D Topological Superconducting Single Photon Detector Devices)
Reporting period: 2023-02-01 to 2024-07-31
The microelectronics industry has managed to extend Moore's Law through innovative device scaling and processor architectures, yet we are approaching fundamental limits of scaling, operation frequency and power dissipation. Deep learning and data-driven computations increasingly demand frequent memory access, resulting in significant power consumption challenges are hard to address efficiently using conventional compute architectures.
As Europe strives to achieve sovereignty in microelectronics technologies through initiatives like the European Chips Act, there is a growing need to shape the future of computation by innovating key functional materials. Superconductors for quantum computing and topological insulators for in-memory computation represent critical materials that could enable next-generation computational paradigms beyond traditional von Neumann architectures.
A historic juncture is nearing as von Neumann architectures and quantum computing platforms start being used together. Their synergistic operations are enabled by emerging quantum materials such as topological insulators, superconductors and single photon sensing layers.
Quantum computing systems, typically based on superconducting transmon or rf-SQUID qubits, and in-memory computing based on spintronics using novel 2D magnetic materials, have emerged as promising complementary approaches. These new materials minimize Joule heating, enable tunable magnetic and electronic transport properties, allow fast switching, and achieve good memory retention. However, the development of these technologies faces a significant bottleneck: the complexity and cost of processing these specialized materials.
Currently, only a handful of institutions—primarily outside Europe, such as Caltech, MIT, and companies like Rigetti—can develop these materials and build proprietary computing systems. This limitation severely restricts the pace of innovation in quantum and spintronic technologies. Despite excellent European materials manufacturing facilities at institutions like Max Planck, Fraunhofer Institutes, TNO, Imec, and CNRS, these materials require dedicated infrastructure due to their sensitivity to equipment cross-contamination.
As Europe strives to achieve sovereignty in microelectronics technologies through initiatives like the European Chips Act, there is a growing need to shape the future of computation by innovating key functional materials. Superconductors for quantum computing and topological insulators for in-memory computation represent critical materials that could enable next-generation computational paradigms beyond traditional von Neumann architectures.
A historic juncture is nearing as von Neumann architectures and quantum computing platforms start being used together. Their synergistic operations are enabled by emerging quantum materials such as topological insulators, superconductors and single photon sensing layers.
Quantum computing systems, typically based on superconducting transmon or rf-SQUID qubits, and in-memory computing based on spintronics using novel 2D magnetic materials, have emerged as promising complementary approaches. These new materials minimize Joule heating, enable tunable magnetic and electronic transport properties, allow fast switching, and achieve good memory retention. However, the development of these technologies faces a significant bottleneck: the complexity and cost of processing these specialized materials.
Currently, only a handful of institutions—primarily outside Europe, such as Caltech, MIT, and companies like Rigetti—can develop these materials and build proprietary computing systems. This limitation severely restricts the pace of innovation in quantum and spintronic technologies. Despite excellent European materials manufacturing facilities at institutions like Max Planck, Fraunhofer Institutes, TNO, Imec, and CNRS, these materials require dedicated infrastructure due to their sensitivity to equipment cross-contamination.
The SuperPHOTON project addressed this challenge by leveraging ERC-funded molecular beam epitaxy and pulsed laser deposition systems specifically dedicated to superconductors and spintronic insulators. The project supplied high-quality, reproducible, and tunable materials to researchers such as metrology institutes and companies, enabling them to explore emerging research needs and accelerate device development. As a breakthrough demonstrator, the project designed and fabricated an efficient topological superconducting single photon detector with a low-cost custom cryostat.
These superconducting single photon detectors developed are critical components in many quantum systems due to their high detection efficiencies, short jitter times, photon number resolution capabilities, high maximum count rates, and low dark count rates. By improving these detectors through the unique properties of magnetic topological insulators, the project demonstrated new applications in topological quantum computing and quantum internet technologies.
The project demonstrated three categories of materials: superconducting doped topological insulators on insulating magnetic iron garnet films, superconducting topological insulator interfaces, and niobium nitride. These materials bridge spintronics and quantum computing, enabling simultaneous ultralow power and in-memory computation capabilities.
These superconducting single photon detectors developed are critical components in many quantum systems due to their high detection efficiencies, short jitter times, photon number resolution capabilities, high maximum count rates, and low dark count rates. By improving these detectors through the unique properties of magnetic topological insulators, the project demonstrated new applications in topological quantum computing and quantum internet technologies.
The project demonstrated three categories of materials: superconducting doped topological insulators on insulating magnetic iron garnet films, superconducting topological insulator interfaces, and niobium nitride. These materials bridge spintronics and quantum computing, enabling simultaneous ultralow power and in-memory computation capabilities.
While topological insulators are promising for single photon detectors, the SuperPHOTON project had to resolve a key challenge during the implementation phase. This problem is the limited absorption of the TI surface and the defects within the bulk of the TI layers. The TI surface layers carry the electrons that are triggered to flow immediately after light is incident on the TI. But the bulk of the TI is either not absorbing the photon or atomic or line defects within the TI may absorb photon without contributing to photocurrent. In either case, the single photon detection efficiency would drop, and the dark count rates would increase. To resolve this challenge, we optimized the crystal growth process and used atomic modelling studies to identify how defects would form and when they would be stable. We also modelled and fabricated heterostructures of TIs to recycle and bounce photons back and forth within the film until they are fully absorbed.
We also designed a compact cryostat which can be used as a desktop system with optical, DC and RF ports. Reducing the cost of the RF, cryostat and calibration parts and protocols is expected to reduce the price per single photon detector by almost 50 times with respect to the state of the art. These results are currently being prepared for submission for peer-reviewed publications and patent filings.
The project enabled new synergies with European National Metrology Institutes. As a result of this project, new topological insulators and their heterostructures are currently being measured for redefining the electrical resistance standards.
The impact extends beyond materials development to enabling critical applications in quantum key distribution for record-setting quantum internet, light detection and ranging, optical time-domain reflectometry, single molecule detection, astronomy, semiconductor inspection, and bio-imaging. The unique sensitivity and ultrafast response of these superconducting single photon detectors could enable quantum computation with advantages over classical approaches and open new frontiers in topological quantum computing.
The project helped supply new quantum materials to the European COST Actions such as CA23136 and CA23134 and European Association of National Metrology Institutes (EURAMET) project 23FUN07 QuAHMET.
The impact of the project and similar advanced quantum materials research has also been evaluated and highlighted in the World Economic Forum report “Embracing the Quantum Economy: A Pathway for Business Leaders.”
Currently, 1 peer-reviewed paper has been published and 4 more are in preparation. 3 patent applications on the materials and devices are being filed as of first quarter of 2025.
We also designed a compact cryostat which can be used as a desktop system with optical, DC and RF ports. Reducing the cost of the RF, cryostat and calibration parts and protocols is expected to reduce the price per single photon detector by almost 50 times with respect to the state of the art. These results are currently being prepared for submission for peer-reviewed publications and patent filings.
The project enabled new synergies with European National Metrology Institutes. As a result of this project, new topological insulators and their heterostructures are currently being measured for redefining the electrical resistance standards.
The impact extends beyond materials development to enabling critical applications in quantum key distribution for record-setting quantum internet, light detection and ranging, optical time-domain reflectometry, single molecule detection, astronomy, semiconductor inspection, and bio-imaging. The unique sensitivity and ultrafast response of these superconducting single photon detectors could enable quantum computation with advantages over classical approaches and open new frontiers in topological quantum computing.
The project helped supply new quantum materials to the European COST Actions such as CA23136 and CA23134 and European Association of National Metrology Institutes (EURAMET) project 23FUN07 QuAHMET.
The impact of the project and similar advanced quantum materials research has also been evaluated and highlighted in the World Economic Forum report “Embracing the Quantum Economy: A Pathway for Business Leaders.”
Currently, 1 peer-reviewed paper has been published and 4 more are in preparation. 3 patent applications on the materials and devices are being filed as of first quarter of 2025.