TU Graz news: What exactly are you currently working on?
Markus Aichhorn: I’m trying to build computer models that simulate the properties of materials. Specifically, I am currently working on mapping the behaviour of solids under real conditions.
What does that entail?
Aichhorn: Our simulations normally show typical ideal conditions. This means a perfect environment, no impurities in the solid, no faults in the system. Of course, it’s not like that in the real world. We try to ensure that our models also take into account what causes defects, what impurities there are, what happens when crystals grow crookedly and so on.
Can you give me an example?
Aichhorn: I often work with oxides. They contain oxygen and because it is very volatile and reactive, this makes it a very unpleasant element. It does a lot of things that you don't want it to do. Typically, oxygen disappears from the crystal and creates oxygen defects. But this only happens in one in 100 cases. This is therefore very difficult to model because it is a very singular effect.
Is that the only topic you are currently working on?
Aichhorn: No. I have the luxury of being able to try out different things. For example, I am currently starting to build up knowledge on quantum batteries together with a master's student. This is a micro version of a battery in which a quantum mechanical system is used to store energy. The background to this is quantum supremacy, which means that quantum physics can do something fundamentally better than classical physics. Quantum computing is also part of this.
I have the luxury of being able to try out different things.
(Markus Aichhorn)
We are also analysing the cathode material of conventional batteries, such as new types of sodium batteries. Where does the sodium diffuse, what distinguishes it from lithium, what effects does it have? There are many elements in a battery that heat up, cool down and move – and we want to simulate this.
Why are you interested in this?
Aichhorn: Good question. Sometimes I just do things because I have learnt them well and can do them. We have methods for this and know that they work for the material to be analysed. And then you work your way from research question to research question.
But I ask myself many research questions – such as those relevant to quantum batteries – simply because I find them interesting. Because I want to understand what's going on.
We are in the area of basic research, aren't we?
Aichhorn: Yes, exactly. I do very little research for which I already have an application in mind. For me, that would create more pressure than joy. And it is a privilege to be able to do research like this.
Fun and enjoyment are important for creativity?
Aichhorn: Absolutely. Especially in your PhD, the first thing you learn is to keep the frustration level high. Very little works at the beginning and you have to be able to deal with that. But the work still has to be enjoyable overall. Research projects are a commitment, sometimes for years. If it's not fun, then it's just tedious for everyone involved.
Especially in your PhD, the first thing you learn is to keep the frustration level high.
(Markus Aichhorn)
Why are you principally interested in this type of physics?
Aichhorn: I've always had a very good connection to physics and already knew at the age of 15 that this would be my life. Like all new students, I didn't know much about solid state physics at the beginning of my degree programme.
When young people think of physics, they think first of astrophysics, particle physics, high-energy physics, cosmology, gravitational waves and biophysics. And right at the very end come the materials. Although everyone has a mobile phone in their hands, the touchscreen is an incredibly exciting material.
Like all new students, I didn't know much about solid state physics at the beginning of my degree programme.
(Markus Aichhorn)
Then you slowly grow into the subject and ultimately the majority of students work in this field later. I find it incredibly exciting that this type of physics always has the fundamental possibility of application. We can test our ideas experimentally. It's not quite so simple with quantum gravity, for example, for which there are around 20 different theories that cannot be tested. I find that very pleasant about the physics of materials. It's down to earth.
Can you tell me what will be happening in your field of research in the coming years?
Aichhorn: For us, this is very difficult to plan. Progress in our field is often triggered by surprising, singular experimental findings. High-temperature superconductivity was many years ago, then came graphene, then, for example, high-pressure superconductivity. And new topics keep popping up that keep the community busy for several years. The latest topic is two-dimensional materials, which can be produced very flexibly and which are also having research done on them at our institute. They are used in electronics and will certainly remain an important topic for several years to come. But above all, you have to remain open and flexible.
