A magnet as small as an atom. Impossible to measure? Not for Aparajita Singha. The physicist holds the new professorship for "Nanoscale Quantum Materials" at TU Dresden. Her tools are diamonds with flaws. She uses them as ultra-precise sensors to detect the smallest magnetic signals in materials. Her work is an important basis for quantum computers and other technologies of the future.
Singha conducts research in the Dresden-Würzburg Cluster of Excellence ctd.qmat. "My passion for quantum sensors began when I wondered whether I could really measure the smallest magnet in the world," she says. What sounds abstract has concrete meaning. At the atomic level there are tiny elementary magnets, the electron spins. Their alignment stores information. While normal computers only calculate with zeros and ones, in the quantum world these spins can be zero and one at the same time. This makes quantum computers extremely powerful.
Method with great potential
Working with NV centers in diamonds is an important research trend worldwide. Things are also happening in Saxony. "Almost all Saxon quantum start-ups are working with defects in diamonds," says Matthias Vojta, spokesperson for the Cluster of Excellence in Dresden. These include several companies from the Saxon quantum network SAX-QT. "This enriches our research activities in collaboration with Würzburg and gives the local industry more quantum power."
Ten people work at Singha's professorship: two postdocs, six doctoral students and one technician. The measurements have to take place in an absolutely pure environment, as pure as in space. Only in an ultra-high vacuum can they achieve the necessary precision. The researcher is convinced that her method has great potential. After all, it is the only measurement method that can also work at normal temperatures.
