In conversation with Luo Tingpeng

You did your bachelor’s degree in China; why did you decide to continue your studies in Germany?

Throughout the world, Germany has a good reputation not only for its companies and products, but also its education. That was one factor for my decision, and the other was my curiosity. Most Chinese students who go abroad choose the US, the UK or Australia, but I was curious about living in Germany. At the beginning, I was unsure about the language barrier. I took an extensive language course, which helped me a lot in day-to-day life, but during my studies it was luckily never a problem. My master’s program and my current work is all in English. Moving to Germany was a big decision and I really had to convince myself at first, but I was sure from the start that I would not regret my choice. Now, almost six years later, it is just as I imagined it. The opportunity to gather international experience and to get to know another culture is very rewarding for me.

How did you come across Fraunhofer IAF?

After having spent some time in the north of Germany I wanted to go back to the south where I lived during my first years here. I also wanted to look for a position at a research institute. One day, I would like to work in industry, but before that I think it is better to start at an institute and Fraunhofer institutes are very close to industry, which makes them a great choice for me. At Fraunhofer IAF I found a relatively new scientific field that immediately fascinated me, which is why I came here. I’m now working with nitrogen vacancy (NV) centers in diamond. It is not a mature technology with many fundamental things still in need of research before it can find its way into applications. This makes it very interesting to work with and an excellent topic for my PhD research.

You work with NV centers in diamond that can have various applications. What exactly are you researching?

I study NV centers for quantum magnetometry. An NV center is a deliberate defect in diamond that makes the material very sensitive to magnetic fields, which is why they can be applied as tiny sensors. The use of single NV centers provide magnetic field strength measurements on the nanometer scale, which was not possible before. Diamond with a large concentration of NV centers can also be used to detect magnetic fields precisely. And a strong advantage compared to other sensors is that NV centers work even with background fields and at room temperature, while many precise magnetic field sensors need to be cooled cryogenically or require cancellation of the earth’s magnetic background field. This makes NV centers in diamond a promising material of which clinical imaging is one possible application I am looking into.

The focus of my work is material characterization. I have a Bachelor’s degree in optoelectronics and Master’s in optics and photonics, so practical engineering is my strong side. When I characterize the diamond I’m not only studying the material, but also the application related to it. I search for possible improvements of the material, in order to improve its performance for specific applications. In the future, I’m looking forward to see its application in the field of clinical imaging, especially the combination with magnetic resonance imaging (MRI) and the prospect to detect brain activity as a replacement of magnetoencephalography (MEG) technology.

How does your workday look like?

I normally get a lot of diamond samples from another group at Fraunhofer IAF that grows diamond themselves. I characterize the samples, which is a long process, considering the amount of relevant properties we need to know. For example, I scan the fluorescence of the samples to calculate the concentration of NV in the diamond or analyze the diamond’s absorption, which is very important for its performance in a laser cavity. Ultimately, we want to use it as an optical laser gain medium in a laser cavity for quantum magnetometry. Another PhD student does exactly that by building up the laser cavity and testing the samples inside the cavity. This gives me important feedback for my characterization of the material. I work like a mediator between material development and application, with the aim to improve both.

What do you like about working at IAF?

Something that is quite different from all the other places I have been to is that the people at IAF collaborate very closely. The groups are quite small, but they all have their specific expertise. Whenever I need help with something my group is not familiar with, I always find someone at IAF or even the whole Fraunhofer society to help me out. The people at Fraunhofer are very willing to help each other. That is something I appreciate working here.

You have lived in different German cities, which did you like the most?

I like Freiburg very much. It’s not too big and not too small, which is very convenient for me. It’s small enough to get around quickly, but at the same time it is never boring. There are a lot of activities and events you can do – sadly, not at the moment, due to Corona. Last year, for example, I went to the wine festival, which was amazing. Additionally, Freiburg has a beautiful landscape with the Black Forest nearby and offers great traveling opportunities to France and Switzerland.

After finishing her B.Eng. in optoelectronics in China, Luo Tingpeng moved to Germany in 2014 to pursue her M.Sc. in optics and photonics at KIT in Karlsruhe and the Max-Planck-Institute for Biophysical Chemistry in Göttingen. Since 2018, she has been working on her PhD on NV centers in diamond for quantum magnetometry at Fraunhofer IAF.