Quantum sensing and quantum metrology are technological fields aimed at improving the accuracy and sensitivity of measurements. Quantum sensors can measure quantities such as time, temperature, and the properties of gravitational and electromagnetic fields with far greater precision than conventional sensors. This enhanced accuracy supports progress in medicine, navigation, climate science, astronomy, and many other critical sectors.
Operating principles of quantum sensors
A quantum sensor works by exploiting quantum phenomena such as superposition and entanglement:
- Superposition. This principle enables particles to exist in multiple states simultaneously, increasing the sensor’s sensitivity to environmental changes.
- Entanglement. When two or more particles become entangled, a change in one particle’s state instantly affects the others, regardless of physical distance. This interdependence adds additional precision and faster response times.
One of the most important techniques underlying quantum sensors is quantum interferometry. This method uses the wave nature of light or elementary particles to detect extremely small changes in space, time, or other physical quantities. For instance, a quantum sensor might use laser beams, atoms, or neutrons to precisely measure the properties of gravitational or magnetic fields. Because quantum sensors can register and distinguish changes of exceptionally small amplitudes, they are significantly more sensitive than classical sensors.
Quantum Metrology
Quantum metrology is the science of measurement based on the principles of quantum physics. It is crucial for highly precise measurements in scientific research, industry, and technology. Quantum metrology primarily focuses on measuring time, electric charge, and mass. A noteworthy example is atomic clocks, which use quantum processes to measure the most accurate time in the world—indispensable in satellite navigation systems (e.g., GPS), where extremely precise timing and synchronization are essential.
Quantum metrology also contributes to developing measurement systems based on optical clocks and other quantum standards. These devices open new approaches to ultra-precise measurements and data collection, elevating the quality of research and technological solutions.
Advantages and disadvantages of quantum sensors
A quantum sensor is more accurate than a simple sensor because it is more sensitive and can detect even the smallest changes in physical quantities such as temperature, magnetic field strength, or gravity. Naturally, this is an invaluable property in scientific research and precision technology.
A quantum sensor operates based on quantum physics, which makes its measurement results extremely precise and reliable. Such quality is unattainable with conventional measuring instruments.
Quantum sensors are difficult and expensive to produce and use. They often require specialized hardware and can only function with utmost precision in tightly controlled environments, for example at very low temperatures. Quantum sensor technology is still in the development stage, which limits its adoption in many fields.
Potential applications of quantum sensors
Industrial and Research Laboratories. Quantum sensors are essential where ultra-precise measurements are needed to meet increasingly tight tolerances, discover new materials, and optimize precision manufacturing processes.
Medicine. Quantum sensors could enhance diagnoses and treatments by measuring the slightest changes in brain waves or cardiac electrical activity, enabling medical professionals and researchers to detect and diagnose neurological or heart conditions with greater accuracy.
Navigation. Providing more precise positioning and motion data could be invaluable for developing autonomous vehicles and advancing aviation. Quantum sensors could function even where GPS signals are weak or nonexistent, such as underground or in outer space.
Environmental Monitoring. By detecting small changes in gravitational or electromagnetic fields, quantum sensors can help track climate changes, predict natural disasters, and observe geological processes.
Kvantandurid Eestis
In Estonia, quantum technology—including quantum sensors—is currently in the research and development phase, but work is already underway in these areas. Estonian research institutions and universities are actively investigating quantum sensor technology for potential applications in industry and scientific research.
AS Metrosert, for instance, is engaged in quantum metrology, developing and implementing various quantum sensors. In 2022, Metrosert acquired a measurement system for extremely low light intensities and, over the coming years, will build the infrastructure necessary to calibrate quantum reference sources and reference detectors—applicable to further research in quantum metrology across telecommunications, medicine, and materials science. This effort builds on previous international research projects in optical science. As of early 2023, a plan has been established to elevate calibration standards for optical quantities, initially in the visible light range of 380 to 780 nm, to the level of a national metrology standard.