Quantum sensors achieve measurement results of unique precision.
Quantum sensors answer questions even before we ask them. In autonomous vehicles, they recognize whether there is a vehicle outside of our field of vision behind the next corner of the house on a collision course with us. Diagnose at checkups for cancer and Alzheimer’s the diseases before the first symptoms appear.
In order to obtain these findings, the sensors analyze the interaction between the atoms of the measurement objects and quantum elements such as electrons. “Because these are super sensitive, the sensors come to extremely precise measurement results,” explains Professor Tommaso Calarco, Director of the Institute for Quantum Control at the Peter Grünberg Institute of the Research Center.
Both energetic states such as temperatures or speeds as well as the location and nature of an object can be measured. Quantum sensors can also visualize molecules and their chemical composition. They achieve a resolution of up to 20 nanometers. At 10,000 nanometers in diameter, human hair is 500 times thicker. Even the smallest viruses are around 100 nanometers in size.
Quantum technology explained
What is quantum technology actually? Why are quantum technologies so relevant? You can read answers to all these questions in our big overview: ” What you need to know about quantum technology “.
Here you can find out why the technology is so relevant for Germany and what research, politics and companies are planning: ” Quantum technology: why Germany must act now “.
Error-free function without calibration
“If we were to entangle two quantum objects in a quantum sensor and use them for the measurement, the sensor would be even more sensitive,” adds Tommaso Calarco. However, unlike quantum computers, quantum sensors usually do not work with the entanglement and superposition of quantum elements. As a result, they are less susceptible to faults than supercomputers and do not have to be operated in cryostatic environments in order to function correctly. Since they compare the measured physical properties with quantities given by nature at the atomic level, they do not need to be calibrated.
“The currently most advanced approach in quantum sensor technology is nitrogen-vacancy technology,” explains Dr Christoph Nebel, Head of the Diamond Components Business Unit at the Fraunhofer Institute for Applied Solid State Physics (IAF). Scientists like him and his colleagues grow the finest needles from artificial diamonds. At their point, they remove two carbon atoms from the lattice structure of the gemstone.
They replace one of them with a nitrogen atom. This has one more electron than the surrounding carbon can bind. Therefore, it falls into the vacancy left free next to the nitrogen molecule. There it becomes the smallest magnetometer in the world and turns the so-called nitrogen-vacancy centre into a quantum sensor. To get more interesting information related to Quantum technology and other Automation and Electrical engineering go to the given link.
A matter of turns
Like every electron, it is in a natural gyratory motion. “This spin creates a magnetic field,” explains Nebel. “This changes when other magnetic fields act on it.” In a nitrogen-vacancy sensor, these are the magnetic fields of the electrons in the atoms of the measurement objects. This scans the diamond needle like an atomic force microscope.
“The electron in the nitrogen-vacancy centre also has a base energy level and an exciting level that is only slightly above it. This level splits when an external magnetic field acts on the electron. The splitting is greater, the stronger the acting field is,” Nebel continues.
Ultimately, this changes the colour and brightness of the light that passes through the diamond needle. By analyzing it, the strength and changes in the external magnetic field and, in conclusion, the nature, energy, movement or location of the measured substances or objects can be identified. Since magnetic fields can hardly be blocked or shielded, electrons in quantum sensors also react to the effects of objects that are outside of the human field of vision – for example underground or behind a corner of a house.
New ways of quality assurance of semiconductors
In the future, semiconductor manufacturers will use nitrogen-vacancy sensors to control the quality of their products. Since chips and memory have to process more and more data without getting bigger, a Pentium processor now contains over 30 million transistors. The magnetic structures on a hard drive are now only 10 to 20 nanometers in size. Whether they have errors can only be detected on this scale with the help of quantum sensors
In addition to nitrogen-vacancy sensors, there are numerous other approaches to achieve high-precision measurement results with the help of quantum physics – such as quantum gravimeters, gravitational-wave interferometers or quantum gyroscopes and accelerometers. They record movements, directions and speeds so precisely that they can navigate precisely by comparing their measurement results with a digital map, even without satellite support.
This makes quantum sensors a key technology for Quantum sensors. “Because there are always GPS shadows, especially in cities, several sensor principles must be used simultaneously for reliable operation of autonomous vehicles. Quantum sensors would be of great help here,” explains Christoph Nebel from Fraunhofer IAF.
Time measurement in unison of the atoms
“Quantum sensors can also detect raw material deposits, oil fields or underground water reserves at great depths based on their gravitational properties,” says Tommaso Calarco, explaining another area of application for the technology.
Quantum clocks are also among the quantum sensors. They measure time-based on the vibration of atoms and provide ultra-precise time references and geographic longitude standards in the aerospace industry. They can also be used to synchronize critical infrastructures such as line and communication networks or financial transactions over long distances.
In medicine, radiologists are already using quantum sensors in special magnetic resonance tomographs. However, such devices have to cool down for two hours after each use and cost up to 1.6 million euros.
No one has yet calculated how much manufacturers could earn with quantum sensors. In 2023, the technology and market research company Intrado estimates that the market for all quantum technologies – i.e. not only sensors but also quantum computers, cryptography and communication – will be a good 13 billion US dollars.
German companies in pole position
German and European companies will account for a large part of this turnover. In 2018, every second participant in the “Zeiss Symposium – Optics in the Quantum World” expected Europe to be a leader in the implementation and use of quantum technologies in 2030. Four out of ten respondents see Asia ahead, only 14 per cent the USA. That was the result of a survey during the congress.
The confidence is no accident. For example, Bosch is currently working with the University of Mainz to develop gyroscopes for autonomous driving that use quantum laws. Quantum technologies are also at the top of the research agenda at Siemens, Airbus, the laser technology specialist Trumpf and the supplier to the semiconductor industry Zeiss
The EU Commission wants to take Europe to the top in quantum technology
The European Commission recently also emphasized the opportunities offered by the technologies in a communiqué to the Council and Parliament of the Community. As part of the European Quantum Technologies Flagship Project, the EU has been funding more than 5,000 scientists and 140 research projects since 2018. It will spend a total of one billion euros over a period of ten years.
In quantum sensing, this money will bear fruit sooner than in quantum computing. The supercomputers will probably only change the world in ten to fifteen years. Quantum computers will probably only change the world in ten to fifteen years. “We will already see substantial progress in quantum sensor technology within the next EU funding period up to 2027,” Tommaso Calarco from FZ Jülich is convinced. “The first prototypes of quantum sensors for autonomous driving could already be available by the end of this period,” the physicist expects.
The range of applications for the technology could also expand considerably by then. “Since we can measure more precisely with quantum sensors than ever before, I don’t rule out the possibility that we don’t even know many things that we could investigate with the technology,” adds Tommaso. If so, quantum sensors would indeed answer questions before we even ask them.