© Fraunhofer IAF
With various innovative approaches, solutions and applications of quantum sensors, a concentrated research infrastructure is gathered in Freiburg im Breisgau with the three institutes Fraunhofer IAF, IPM and IWM—forming the Quantum Sensing Hub Freiburg.
Quantum Sensing Hub Freiburg is pursuing two classes of quantum magnetometers with complementary properties: the development of magnetometry based on both optically pumped alkali atoms (OPMs) and nitrogen-vacancy centers in diamond (NV centers). With our pooled know-how regarding next generation quantum magnetometry based on these approaches, we enable the development and realization of application specific measurement systems.
NV centers are individual atomic systems that act as highly sensitive sensors. Their unique advantage is their potential to be operated at room temperature and on background fields. They allow for extremely high spatial resolution and are being utilized in different imaging measurement methods.
In OPMs, alkali atoms are used as probes for the magnetic field. Laser light is used to prepare all atoms in the same state. In an external magnetic field, the atoms then undergo a synchronous ›Larmor precession‹. Its frequency is proportional to the local magnetic field. In the basic operating mode, this precession signal can be read out optically and provides a calibration-free measure for the magnetic field.
In the most sensitive configuration, OPMs reach (and even surpass) the sensitivity of cryogenically cooled SQUID magnetometers and can be used for the detection of magnetic signals of the brain. Due to the highly sensitive measurement, a shielding from ambient magnetic noise is mandatory to reach the highest sensitivity values.
| Sensing Principle | Sensitivity | Spatial resolution |
|---|---|---|
| Available systems | ||
| Optically pumped magnetometer (OPM) | < 15 fT/√Hz | < 5 mm |
| Scanning probe magnetometer (NV) | < 10 μT | < 30 nm |
| Widefield magnetometer (NV) | < 10 μT | < 1 μm |
| In development | ||
| Laser threshold magnetometer | 1 fT/√Hz–30 pT/√Hz | 100 μm–1 mm |
| OPM-based camera (1000 pixel) | 25 pT/√Hz | 100 µm |
| RF sensors (NV) | 0.1–10 GHz | < 1 μm |
With our unique infrastructure we offer the ideal starting point for research and development work in the field of magnetometry with quantum sensors. The areas of application of our measurement technology and systems spans from material characterization, industrial process monitoring, space equipment qualification, nanoelectronics to biomedical applications.
Our partners from science and industry have the opportunity to evaluate the innovative potential of quantum sensors for their specific requirements. With our broad range of high-resolution and high-sensitivity measurement systems we have the quantum sensing solution for your individual measurement or R&D needs.
"The high sensitivity of OPMs allows us to develop novel magnetometry applications for process analysis, material testing and space applications."
Dr. Peter Koss
Gas and Process Technology
Fraunhofer IPM
"With its unique characteristics, NV-center based Magnetometry has the potential to push the magnetic characterization of industry-relevant materials one step further."
Niklas Mathes
Quantum Sensing
Fraunhofer IAF
"Imaging magnetic stray fields at the nano- to micrometer scale can allow for the establishment of novel kinds of refined material models.”
Dr. Simon Philipp
Meso- and Micro-Mechanics
Fraunhofer IWM
"At the Quantum Sensing Hub Freiburg, we work together with partners and customers to develop innovative technological applications.”
Deborah Mohrmann
Business Development
Fraunhofer IAF
Fraunhofer Institute for Applied Solid State Physics IAF