Magnetic field measurement on the atomic level
Sensor technology in a new dimension
Up to now, highly sensitive methods for measuring magnetic fields have had decisive disadvantages: They either require very large setups, have high power consumption, the components used suffer from self-heating or the fields to be measured are influenced by eddy currents. A microwave-free quantum magnetometer can be set up inexpensively and compactly. Its high sensitivity makes it interesting for use in numerous fields of application.
What is a quantum sensor?
Quantum sensors use laws and processes based on quantum technology. Physical quantities such as temperature, velocity, electric and magnetic fields as well as positions can be determined with a precision that was previously unattainable. Currently, research institutes and industrial companies such as Turck duotec are preparing quantum sensor technology or quantum magnetic sensor technology for practical application.
Microwave-free, quantum-based magnetic field sensor for use under the most adverse conditions
The sensor to be realized uses high-density NV diamonds that emit red fluorescence when irradiated with green light, which is affected by magnetic flux densities. In this way, a highly sensitive and dynamic as well as galvanically isolated magnetic field sensor can be produced. Such a sensor functions without the application of microwaves compared to other NV-based sensors.
The compact sensor can be built inexpensively, while a miniaturized structure already exists. Operation is possible over a wide temperature range, including room temperature.
The measurement method
The sensor system uses the magnetic field-dependent red fluorescence of high-density NV diamonds. The red fluorescence is produced when these diamonds are irradiated with green light. The sensor uses the magnetic field dependence of the spin states of the NV centers and the associated change in fluorescence intensity to measure magnetic flux density.
Advantages of the microwave-free, quantum-based magnetic field sensor:
- Simple and inexpensive design
- Freedom from property rights, legal usability
- Unproblematic sensor element alignment in a later series production, since no crystal alignment is required
- No sensor reset required, no hysteresis or memory effects
- High response speed of the fluorescence signal (<20 ns)
- Scalar magnetometry
- Large working distance possible
- Sensor element surface with maximum mechanical hardness (10);
can be brought into direct contact with moving surfaces.
- Optical sensor element with purely optical coupling without microwaves possible e.g. with optical waveguides:
- Galvanic separation of magnetic field measurements and evaluation electronics with data bus connections (>1kV, important for current measurement in batteries for electric vehicles main drives).
- No self-heating as with current measurement using bus shunts
- Chemical inertness of the sensor element if the diamonds are coupled via an optical fiber (placement in electrochemical cells such as batteries is possible)
- Measurements at very high temperature (up to ~720°C = oxidation limit) and very low temperature (e.g. liquid N2, liquid He temperature) possible
- Measurements in contaminated areas possible (e.g. during medical examinations in radiology).
Possible fields of application
Due to the wide temperature range, its radiation hardness as well as the possibility to function under very adverse environmental conditions, the quantum-based magnetic field sensor is suitable for:
Mechanical and Plant Engineering
High Voltage Technology
As an EMS and E2MS service provider, Turck duotec has more than thirty years of expertise in the production and development of electronic component groups/sensors and the corresponding know-how in the industrialization of products. Turck duotec is a strategic investor in Quantum Technologies, a company for sensitive material and magnetic field detection.
Together, the two companies are working on the development of a market-ready quantum magnetic sensor, with the aim of expanding the portfolio for customers in the segments of medical technology, energy, communication and many more.