Quantum sensors open up entirely new possibilities for detecting material fatigue at the atomic level, long before conventional methods reveal any damage. To realize this potential, the quantum mechanical coherence of the sensor substrates must be ensured. The coupling between the sensor and the test specimen must combine mechanical robustness with quantum-physical sensitivity. We are researching challenges like these to ensure the safety of tomorrow’s components.
The Next Level LandBW 2024/25 project is breaking new ground in non-destructive materials testing – with quantum sensor technology at the highest technological level. Ultra-sensitive NV diamond sensors and optically pumped magnetometers (OPMs) are used to reveal magnetic structures in the micro range that were previously hidden. The aim is to capture magnetic “fingerprints” of materials as starting points for material improvements and methods for fatigue detection, prediction, and prevention.
Project profile: Next Level LandBW 2024/25 – Quantum Sensors in Material Characterization and Testing - Fraunhofer IWM
In the collaborative project SiQuRe, quantum physics models and simulation calculations were used to investigate the extent to which color centers in diamond crystals - which can be addressed as qubits - can be arranged regularly in large numbers and utilized as qubit registers for the construction of quantum computers.
In the follow-up project SiQuRe II, the conditions for robust quantum states in coupled spin systems consisting of NV centers and 13C atoms were investigated to explore their potential as qubits for solid-state-based quantum computers. The goal was to characterize essential quantum properties and analyze the scalability of these systems.
Both projects have yielded reliable findings regarding which quantum properties can be reliably achieved under realistic materials conditions for specific register sizes, and what requirements this places on materials quality and process technology.
Project profile: SiQuRe: Modeling and simulation of qubit registers made of chains of NV centers on dislocations in diamond – Fraunhofer IWM
Project profile: SiQuRe II: Modeling and simulation of NV-based qubit registers – Fraunhofer IWM
Stability and electronic structure of NV-centers at dislocation cores in diamond, R. Ghassemizadeh, W. Körner, D. F. Urban, C. Elsässer, Phys. Rev. B 106,174111 (2022) Link
Coherence properties of NV-center ensembles in diamond coupled to an electron-spin bath, R. Ghassemizadeh, W. Körner, D. F. Urban, C. Elsässer, Phys. Rev. B 110, 205148 (2024) Link
Spin coherence in strongly coupled spin baths in quasi-two-dimensional layers, P. Schätzle, R. Ghassemizadeh, D. F. Urban, T. Wellens, P. Knittel, F. Reiter, J. Jeske, and W. Hahn, Phys. Rev. B 110, L220302 (2024) Link
The QMag project brings quantum magnetometry from the research laboratory to industrial application. Two imaging sensor solutions have been developed that can measure even the smallest magnetic fields with the highest resolution at room temperature – a milestone for non-destructive materials testing. While NV centers in diamond atomic lattices provide microscopically accurate magnetic field images, optically pumped magnetometers (OPMs) enable the detection of the slightest changes in the materials state – even before the first signs of damage become visible. At Fraunhofer IWM, this made it possible to detect signs of fatigue in materials at an early stage and analyze them specifically using simulations. Micromagnetic simulations were used to calculate the size at which materials defects on the surface, cavities, or inclusions measuring a few dozen nanometers are still detectable at a given surface roughness. Whether in chip manufacturing, biomedicine, or process monitoring, quantum magnetometry opens up new avenues for precision, safety, and efficiency in high-tech industries.
Project profile: QMag - Fraunhofer IWM
Theoretical limits of magnetic detection of structural surface defects at the nanometer Scale, W. Körner, D. F. Urban, and C. Elsässer Körner, Nondestructive Testing and Evaluation, pp. 1–15. doi: 10.1080/10589759.2024.2363282 (2024) Link
Influence of extended defects on the formation energy, the hyperfine structure, and the zero-field splitting of NV centers in diamond, W. Körner, D.F. Urban, and C. Elsässer, Phys. Rev. B 103, 085305 (2021) Link
Influence of (N,H)-terminated surfaces on stability, hyperfine structure, and zero-field splitting of NV centers in diamond, W. Körner, R. Ghassemizadeh, D. F. Urban, and C. Elsässer, Phys. Rev. B 105, 085305 (2022) Link
Stability and electronic structure of NV-centers at dislocation cores in diamond, R. Ghassemizadeh, W. Körner, D. F. Urban, C. Elsässer, Phys. Rev. B 106,174111 (2022) Link
Fraunhofer Institute for Mechanics of Materials IWM