Personal interview of Robert Fickler, experimental quantum physicist

In 2022 the Nobel prize in Physics was granted Alain Aspect, John F. Clauser and Anton Zeilinger on their work in pioneering quantum information science. Tampere University’s Associate Professor Robert Fickler’s PhD work was supervised by Anton Zeilinger, one of the winners. Who is Robert Fickler and why he got interested in research and quantum physics? What kind of students start researching?

Many times, top researchers’ work is described through their research publications in scientific terms. Let’s find out who is the person behind the research and what motivates a young student to start research work and become as Associate Professor at Tampere University in experimental quantum optics.

What was the start of your interest towards physics or photonics?

Physics was the topic in school I liked most, and I had no problem with it, and therefore I wanted to also continue studying physics. At that time, I also wanted to do something with designing, because I was drawing the lot in my free time and liked that. But eventually, I decided that the job would be much more interesting, if it’s a technical job and not a design job. Thus, I decided to study physics which was the most interesting field for me. During my studies, I also thought about maybe becoming a teacher, maybe working in industry, or trying to become a researcher. In the end, researching was the most interesting thing for me, which is realized during my Master thesis in physics. 

What was the main thing that turned it to research?

I think it was the interest in the fundamental things of nature, the fundamental understanding of physics and the world as it is. During my studies, it was also possible to do additionally a bachelor’s in philosophy, which attracted my attention, and I began to also look a little bit into philosophy because philosophers also question very fundamental ideas. I enjoyed it very much, but I also realised I’m a physicist. So, I guess the natural decision was to go towards quantum physics, where I’m now, because quantum physics experiments also question sometimes fundamental concepts and explore very basic ideas about the world.  In general, I think it’s nice to see applications coming out of basic research, but I’m mostly interested in fundamentally understanding physical concepts a bit better, so I consider myself a fundamental researcher.

Have you studied in different countries?

I have started my studies in Germany. After my master, I decided I want to continue doing research in the form of a PhD and went to Austria. Still fascinated by fundamental questions, I looked for research groups that do fundamental physics experiments and I found a group in Vienna, Austria. My PhD supervisor, Anton Zeilinger, worked in Vienna on fundamental questions of quantum physics by doing quantum optics experiments, and I was super-interested in that, also from the philosophy side. So, I applied for a PhD position and was lucky enough to get it. Later on, I worked also in Canada as a postdoc and then came to Finland, Tampere University.

What is the philosophical part in the physics?

I think, in quantum physics, some of the concepts are so counter-intuitive and mind-boggling that they do not make sense from an everyday perspective, and this is where the philosophy comes in. Usually in physics, we make a simplified model of the world to understand how the world works. But although these simple models that we know from our everyday life work quite nice on a macroscopic level, in quantum physics they do not work anymore. This weirdness of quantum physics got me really interested, as it makes you question, what do we actually describe with our theory? Or even more extreme, what can we describe with our theory at all? This question is already a very philosophical question. In quantum physics, such questions often come up so it can be seen as a meeting point between physics and philosophy, which is super interesting for me. But of course, I’m still a physicist and not a philosopher so sometimes it’s also just nice to have hard, natural science results in the lab.

What is your main research field?

It’s quantum optics focusing on experiments with complex structures of single particles of light, so-called photons, and what we can do with them. The group is called Experimental Quantum Optics. But of course, in the end quantum optics experiments are also optics or photonics experiments, so that the things we do in the lab are up to a certain level very similar to the lab work in other non-quantum optics labs. The difference in our work is that we usually work with very faint light. So faint, that light turns into single photons. These particles of light show these counterintuitive quantum features, e.g., sometimes they behave like a wave similar to water, sometimes they behave like a particle similar to a ball. In addition, multiple photons can show correlations called entanglement, a feature that we also do not know form our everyday experience. Well, these effects are what we are researching.

How many people are there in your research group?

At the moment there is one Bachelor student, one Master student, four and a half PhD students, and a postdoc. The half PhD student means that she works also in another group, the nonlinear optics group of Mikko Huttunen.

What is your research group’s relationship with PREIN Flagship?

Now in the second phase of PREIN Flagship, we are embedded in the new work package called Quantum Technologies. In photonics, many efforts are now also going towards quantum technological applications, which means that nowadays we learned to use these weird quantum effects for actual technologies. We have a lot of expertise in the PREIN consortium already, so I think that we nicely fit in PREIN. There is a also different expertise in the quantum domain at the University of Eastern Finland, Aalto University or VTT, and I think it’s a nice combination.

If there were students who are now studying physics, but they are not in photonics or quantum photonics, why they should be interested in?

Photonics is such a broad field! If you are slightly interested, I think there’s really something for everyone. Of course, if you’re interested in other physics areas and not at all in photonics, maybe it’s the wrong field. But as soon as you think optics could be interesting, there will be something for you. Already within Tampere University, but especially within PREIN, there’s so many different research groups that you will find something that you enjoy working on. It could be applications like developing novel lasers or new materials with fancy optical properties, or it could be fundamental research on fast light phenomena or quantum optics. I would say, there is something for everyone. And even if you don’t want to stay in academia, there’s plenty of jobs. There are many, many companies working with or on photonics devices and various spin-off companies that are now commercialising optics research from a few years back. With all that in mind, I think choosing photonics will give you many options after studying or after doing a PhD.

The same holds nowadays also for quantum photonics research. There are more and more companies applying quantum optical effects in these quantum technologies, e.g., quantum cryptography or quantum computing. There is an actual world-wide boom going right now which is termed the second quantum revolution. So, it is safe to say that even if you are interested in very fundamental quantum effects, you will also be able find a job afterwards in case academia is not for you.

How can you specialise in photonics at Tampere University?

I would say if you’re here at Tampere University and you study physics, after the Bachelors, you can specialize for example in photonics. It will give you a broad knowledge at first, followed by a really good education in photonics with very broad expertise and experience. For example, we have plenty courses to choose from and we have summer jobs or lab experiments, where you get a feeling about what the different fields are and in what you want to specialize.

What is your target in your research now?

As said earlier, the group is mostly working on fundamental ideas. As our research is based on good ideas, we sometimes start to go in one direction and along the way we realise, there’s something more interesting and adjust our original research goal. This is great fun as it gives you enough freedom to be creative and follow your genuine interest. 

In general, the focus in our quantum optics experiments as well as in our classical optics experiments lies on structuring light. This means that we are studying complex shapes of light fields or single photons. This sounds maybe a bit strange, but one can modulate light in such a way that it shows up beautiful complex patterns when you image it with a camera, or you can give it a complex colour spectrum. In our research, we increase the complexity of these shapes and see what we can do with it for single photons in the quantum domain. Sometimes this also means that we need to develop novel techniques to see the effects we are studying. So, our research essentially involves both studying fundamental quantum physics effects and develop new devices and demonstrate applications of them.

How easy it is to keep your mind in the focus?

When it comes to diving into quantum physics effects, it’s not too difficult as it is our pure interest. However, of course, in my position, there are quite many organising tasks such that you get often side-tracked and you struggle with finding time to focus on research tasks. But I guess this comes with my position, so I am happy to have a great group that then looks deeper into our ideas and implements the good ones.

How do you work with your research group?

Usually, there’s some idea coming up, sometimes from a group member, sometimes in discussions, and quite often actually on conferences. Sadly, the latter was a bit missing over the last years of COVID, but when you are not in your daily routine and you have more time to discuss physics with group members or colleagues, ideas tend to pop up. Then, very often there’s one person, who is particularly interested and will mostly work on the idea, hence, takes over the lead. The person then involves others that are interested, and we sit together to discuss, reshape, and refine the idea. If the idea survives our discussions and initial calculations, we do an experiment. The responsible person is usually the one that then implements the idea in the lab, analyses the data, presents it to the others. Once we are happy with the results, the leading person starts writing a draft of a manuscript and we all work on it until it is published. It’s always a team effort and very often during one the steps in the process, new questions and ideas come up so we have something to work right away afterwards.

What is the timeline for research?

Well, this is difficult to say but optimistically, once we figured out how the idea can be implemented, an experiment might be doable in a few months. However usually, it takes not only a few months but maybe the estimated time multiplied by pi, which is roughly 3. This would be a more realistic time scale. The reason is that there’s always something that doesn’t work, or we must develop first. As an example, small, short projects might take a half a year, from starting the experiment until you have results. In addition, there is then the time to write a manuscript and get it published, which can easily take another six months. And then there are experiments that are more challenging and naturally take a longer time to build and obtain results. They can take up to one, two, or even three years. Now, we are starting a new very ambitious project, where we plan to do the things that we usually do with light with charged atoms, which is quite more complicated as we need vacuum chambers and shielding etc, to not destroy the fragile quantum effects we want to observe. To get the first breakthrough results, I think it will take us at least three maybe up to five years.

Thus, in research having an output in the form of a publication within a year feels fast, which from the outside might sound very slow.

What kind of person is fit to be a researcher?

That’s a good question. I think research can fit to very different personalities, at least I’ve met researchers with very different personalities. I think there is two things that you must have as a researcher. First, endurance because whatever you do, it’s usually not working right away. So, you must be patient enough and willing enough to continue working, because it’s always problem-solving because you do something that nobody has done before and, thus, there are no blueprints for it. Because this work is often cumbersome, you also need a good motivation for the work, so I think genuine interest is the second thing that is of importance.

Working alone and in teams?

Although I think that research is a team effort, the lab work is usually a single person’s effort. Of course, if you have problems in the lab, talking to your colleagues will help and is often even required to solve the problems through discussions. Thus, we work quite often alone in the lab on the actual implementations but at the same in the team jointly on the project.

What kind of international co-operation with other research groups there is?

Partly our collaborations stem from the fact that I didn’t study in Finland, nor did I do a postdoc or PhD here. Hence, my scientific network is connected to my earlier places, so mostly Austria, Germany, and Canada. In addition, some work we did attracted attention of researcher from other countries, e.g., France, Latvia, and Spain, who then approached us with new ideas which we are currently implementing together.

Are there differences in where you would like to do your job?

The lab work here is pretty much like the lab work was in Canada and Austria. The difference is more at the university, I would say. I found that here the work environment is really nice with flat hierarchies, which I like. I also think that the local students are very well educated, which makes it nice as group leader to work with them. So, I’m very happy to be in Finland. 

Of course, sometimes it is hard to attract talented people from abroad as the north is not for everyone. And, as mentioned before, I would prefer having less administration work to do myself, but overall, I am at a place where I enjoy being.

Do you work all the time with your brains to the research, or how do you relax?

Well, I think researchers work all the time on the topics and ideas they had during the day because it never gets completely out of your head. I guess, that is not just true for me. It started for me already during the master thesis, when I began to actually do research and got really interested in the work. If you are excited about your work, then even if you go home the brain continues thinking about it. It’s a bit like when you have a riddle that you really want to solve. For me it was the problems in the lab that I wanted to solve, and it is now the ideas that we have, which constantly are going around in your head. I guess this is a natural process, maybe even required as it often leads to a better understanding and finding of solutions when you are not even focus on it at weird times of the day. Sometimes, this can be a bit stressful, however, mostly it is also a joy. But relaxing is also important such that I tell my students, take their time off. And for myself too, e.g., when I have a longer holiday, I tell everyone I’m not reachable. No email, no phone, nothing, because it gives you a fresh view on things and new ideas.

How do you relax?

Sports mostly, e.g., I go cross-country skiing and snowboarding in the winter, and I like volleyball and like to go hiking, so many things I would say. I also like to ride a motorbike although I think on my level, I would not consider that as sports, because the motor does everything for me. And I enjoy meeting with friends.

How long have you been in Finland?

Now, four years and I am still really enjoying it. I guess, when I was working in Canada, which is quite similar in the east part in terms of nature and emptiness, I realized that I enjoy this real, untouched nature quite a lot. It was also part of the reason why I came here. Going to the nature to hike and have a quiet, peaceful time is something that I really like to do for relaxing.

What’s going to happen next with your research?

In addition to the research that I already mentioned, where we investigate new states of light and their quantum features, we have two longer-term projects going on. One started already, the other one is currently starting. In the first one, we are developing a technique, where we integrate light shaping techniques into a small glass chip. We do that by shooting a strong laser into the glass such that we carefully damage it in very small regions and with that we can change the shape of light when shining it through the glass. The other one I already mentioned earlier, where we are now setting up an atom physics experiment funded by the EU. As mentioned, this project is very ambitious but there is also a lot of new physics to be discovered without any application yet. This project will be a lot of fun as we will be the first one to set up such an experiment, which means that we will learn a lot and hopefully not just from mistakes that we will make along the way but also in terms of new fundamental quantum effects.