Professor Teemu Ojanen studies exotic quantum phenomena with both feet off the ground

The research interests of Professor Teemu Ojanen focus on quantum condensed matter theory –  a branch of physics that studies the properties of matter – or more specifically on topological phenomena in quantum matter and quantum entanglement. Topological materials can exhibit unusual macroscopic, electrical, magnetic and thermal properties in excited states. Quantum entanglement means that the components of a system become inextricably linked and assume a collective identity where they no longer perform an independent role. For example, quantum computers are based on quantum entanglement.

The study of quantum condensed matter theory is very different from both particle physics and cosmology.

“The properties of matter can be studied in a laboratory that is no larger than an ordinary garage, whereas particle accelerators can be vast – tens of kilometres long – and employ tens of thousands of people. And what is even more surreal is that quantum physicists and particle physicists study phenomena at different energy scales,” Ojanen points out.

Still, despite being at the opposite ends of a broad spectrum, all these fields of research closely resemble one another from a theoretical perspective: they all seek to uncover the mysteries of the universe and use this knowledge to address the manifold challenges facing humanity.

“The beauty of theoretical physics lies in seemingly unrelated phenomena being so similar at the level of human cognition,” he describes.

Quantum computers and energy-efficient electronics from quantum materials

Teemu Ojanen studies materials that exhibit exotic and exciting quantum properties and phenomena. He believes quantum materials will be widely used in the future. Quantum technology has enormous potential.

“It is interesting to investigate whether qubits, the basic units of quantum information, could be made from the quantum particles found in quantum materials. For example, quantum computers could then be based on quantum materials at a hardware  level,” he says.

Quantum materials have excellent electrical and magnetic properties and could be used to develop, for example, electronic components with lossless power transmission. Large data centres generate a massive amount of heat, which in the worst-case scenario is wasted. This means quantum materials could help to save a tremendous amount of energy.   

“Even a slight improvement in energy efficiency would save a huge amount of energy globally,” Ojanen says.

Breakthroughs are possible but not guaranteed

In science, success is inherently unpredictable. Scientists carry out basic research to explore interesting questions and phenomena from multiple angles –- and there is always the possibility of both success and failure. Basic research lays the groundwork that paves the way for practical applications.

Teemu Ojanen points out that many great inventions, such as the internet, are the result of a happy accident. One cannot simply sit down and set out to achieve a breakthrough. Revolutionary technologies often come about as a result of serendipitous discoveries.

“For example, the World Wide Web is a byproduct of basic research in particle physics. The internet was originally conceived to enable physicists at CERN to easily communicate and share information,” he says. 

“There is a long way to go before my research findings can be turned into practical applications. However, I will be very much surprised if quantum materials do not begin to play a pivotal role in high tech manufacturing in the next few decades,” Ojanen notes.

Propeller head with a lifelong fascination with the universe

A self-confessed technophile, Teemu Ojanen became interested in physics as a schoolboy. He grew up in a family of engineers, so natural science was the obvious choice as a field of study. Growing up, he also had ample access to popular science books: the family bookshelf contained books by Stephen Hawking and publications by the Astronomical Association URSA.

“I started pondering the great mysteries of life at an early age. I was enthralled by the universe and my place in it. Nowadays I am happy to study concrete everyday questions as well,” Ojanen laughs.

Being the father of two small children, Ojanen is busy both on and off campus.   

“I have no special ambitions. I am only looking to carry out research projects that interest me and my reference group. I occasionally go cycling and play racket sports. And reading – fact, fiction and comics – is a way of life for me,” he says.  

For Teemu Ojanen, research is a long-term task, a slow process, a never-ending thirst for learning.

“I can never stay idle for long. I always have to keep my brain ticking,” Ojanen says.

Professorship enables a focus on research

Teemu Ojanen wrote his master’s thesis on theoretical physics at the then Helsinki University of Technology (now Aalto University) in 2003 and went on to complete a dissertation on quantum phenomena in mesoscopic physics four years later.

After receiving his Doctor of Science in Technology degree, Ojanen worked as a researcher at Freie Universität Berlin for two years and at Harvard University for one year before returning to Aalto University. In 2019, he took up a tenure-track appointment at Tampere University. Ojanen was appointed as professor of computational physics in the Faculty of Engineering and Natural Sciences (ENS) at Tampere University on 11 October 2021. 

Ojanen leads the Theory of Quantum Matter research group, which comprises four researchers, two doctoral researchers and a varying number of students working on their master’ thesis. Besides conducting research, he delivers lectures on quantum mechanics. The professorship was a major milestone for Ojanen.

“I could not carry out research without being a professor. Research is all-consuming and takes a great deal of time. I could not do it properly if I had a  heavy teaching burden as well. The key is that I have very smart post-docs and students helping me,” Ojanen compliments his group.

In the future, Ojanen is especially keen to study quantum information, quantum computers and quantum simulations from both theoretical and practical perspectives. He believes first-generation quantum simulators and computers, which have only recently become available to scientists, will evolve rapidly over the next few years.

Ojanen engages in research collaborations with researchers in the Department of Physics at Aalto University, among others. His projects have been funded by the Academy of Finland and Helsinki Institute of Physics.

Further information

Teemu Ojanen
teemu.ojanen [at] tuni.fi

Text: Anna Aatinen
Photo: Jonne Renvall