Quantum sensor and measurement technology—Precision redefined

How quantum sensors work

The ultra-precise sensor and measuring systems make use of quantum mechanical phenomena such as the entanglement of individual atoms and photons. This allows the smallest changes in the environment to be recorded, be it changes in magnetic or electric field strengths, temperatures, pressures or frequencies, or even rotational, acceleration or gravitational forces.

Two basic principles

Two types of quantum sensors are currently in use:

• Solid-state quantum sensors detect magnetic fields, temperatures, pressures, accelerations or the position and orientation of objects. Their actual sensor elements are often only nanometers in size.
• Atomic acceleration sensors use laser-cooled matter waves—or their laser-induced interference signals—to measure accelerations, rotations or gravitational forces.

Quantum sensor technology in use

„Native Sensing“ for human-machine interface

Quantum magnetometers can detect magnetic fields in pico-tesla resolutions. Biosignals from the human body can be recorded without contact in order to control prostheses, exoskeletons, cobots or perspective digital devices. This quantum-sensory “native sensing” has the potential to be a game changer in the design of any human-machine interface. Miniaturized chip-based quantum gyroscopes for high-precision and drift-free rotation measurement based on the frequency of the nuclear spin of individual atoms also hold great potential. In the future, this technology could find its way into aircraft, vehicles, ships and submarines through its use in satellite positioning.

Polarizers for magnetic resonance imaging

Quantum sensor approaches are also promising in medicine, biotechnology and chemistry as well as material analysis and quality control: nanodiamond-based polarizers, for example, are expected to make procedures such as magnetic resonance imaging orders of magnitude more sensitive; among other things, in terms of earlier detection of cardiovascular disease or cancer based on minimally altered magnetic fields. The approach can also be used in industry to detect tiny cracks and shape deviations via magnetic field signatures. This is interesting wherever work is carried out in the micron, nanometer or even sub-nanometer range.

Entangled Photons for new imaging methods

New quantum sensing approaches could also solve a dilemma in tissue examinations: the use of entangled photons of different wavelengths makes it possible to apply soft optimally absorbed light in tissue, for which detectors have been lacking until now. The remote effect of entanglement virtually closes the gap: this is because the state of the photons in the tissue can be read outside from the entangled photons of the other, easily detectable wavelength.

Quantum imaging with gentle effect

The use of entanglement is also promising in quantum imaging to observe processes in living cells for hours at high resolution without damaging them with high doses of short-wave radiation. This is because the light in tissue is different to that used for imaging. Using similar methods, quantum spectroscopy is also opening up the way to higher resolutions and more precise analyses.