Applied Physics at TU/e

Nano, Quantum and Photonics at TU/e

Society faces significant challenges in the future and will only be able to overcome them through the right combination of fundamental research, applied science and meaningful minds.
TU/e’s Department of Applied Physics is organised around three disciplines:

  • Fluids, Bio and Soft Matter
  • Plasmas and Beams
  • Nano, Quantum and Photonics

The department includes twelve research groups. Each group is tasked with generating a strong scientific knowledge base in relation to their specific topic, presenting a clear external profile, facilitating the individual PIs (Principal Investigators) active in the groups, and maintaining a sound flow of external funding. The department’s applied science activities are valorised based on four themes: Smart Materials and Processes, Renewable Energy, High Tech Systems and Engineering Health.

This interview focuses on fundamental research and the applied science spin-offs in the area of Advanced Nanomaterials and Devices (Professor Erik Bakkers), Computational Materials Physics (Assistant Professor Shuxia Tao) and Physics of Nanostructures (Assistant Professor Reinoud Lavrijsen).

Why does TU/e have such an outstanding reputation in Applied Physics?

Erik: “TU/e is one of the best-equipped universities in the world. And we are globally respected, as demonstrated by the funding awarded to us recently under a 4 million euro ERC grant for research into Quantum Materials. There is a unique and highly successful relationship between fundamental researchers and applied scientists at TU/e. That open interaction and our close links to industry make us uniquely successful in answering the big questions of the future: Where will our energy come from? How are we going to tackle climate change? How are we going to maintain health when our antibiotics are no longer effective? How are we going to cure cancer?”

Shuxia: “In addition to my work here at TU/e, I spent three years at the NIKHEF physics institute in Amsterdam, which focuses specifically on one area. The most striking difference between the two is that TU/e is really polyvalent and covers a much broader spectrum. That versatility leads to greater cross-departmental synergy and astounding breakthroughs. I also love the spirit of open collaboration in the Netherlands.”

Reinoud: “After studying Engineering Physics at Fontys University of Applied Science in Eindhoven, I worked at Cambridge University as a post-doctoral research associate and full research fellow before coming to TU/e. My conclusion is that we can measure ourselves against the best in the world in terms of fundamental research. I would also agree that our willingness to collaborate with fellow academic institutes and partners in industry gives us a head start when it comes to societally meaningful science.”

What have you focused on during the past 12 months?

Erik: “Thanks to recent improvements in the way we produce nanowires, we have seen the first signs that Majorana particles actually exist. They are named after an Italian physicist, Ettore Majorana, who predicted their existence in 1937, and then disappeared mysteriously without a trace just one year later. These particles are fermions that are their own antiparticle. This development brings super-fast and super-energyefficient quantum computing a step closer because you can potentially connect two Majorana particles to each end of a nanowire and then switch their quantum states. In other words, a 0 and a 1: a quantum bit. ”

Shuxia: “Perovskite solar cells are cheap to make, much cheaper than silicon cells in fact, but the material degrades very quickly over time. Using computational modelling based on the laws of quantum mechanisms, I have been working on the fundamental understanding of the electronic structures and improving the stability of the perovskite materials. Together with colleagues from Peking University, we have recently discovered a way of stabilising perovskite solar cells to increase their potential service life. Our approach involves adding a small amount of fluoride during the fabrication of the perovskite films. Just like fluoride in toothpaste, the fluoride ions form a protective layer around the crystal. The initial results are very encouraging: these solar cells retain 90 percent of their initial efficiency after 1000 hours of operating under extreme test conditions. We still have much to do though as the solar industry expects solar cells to retain at least 85 percent of their efficiency after ten to fifteen years.”

Reinoud: “I have been involved in an exciting project with other researchers at Johannes Gutenberg University (JGU) (Germany), Peter Grunberg Institute (PGI), Daegu Gyeongbuk Institute of Science and Technology (South Korea) and Sogang University (South Korea). We have discovered three-dimensional spin structures, which could be used as the basic units of magnetic storage devices of the future. We also succeeded in demonstrating an unexpected interaction that occurs between two thin magnetic layers separated by a nonmagnetic layer. Usually, the alignment between spins is parallel or antiparallel. In this case, the spins in the two layers are twisted against each other. More specifically, they couple to align perpendicularly, at an angle of 90 degrees to one another. We now understand this fundamental interaction, but a commercial product is still several years away. Further engineering and optimisation are required before this interaction can be used in future 3-dimensional data storage and logic devices.”

That sounds very futuristic! Where do you expect to be in three years?

Erik: “Having demonstrated the existence of Majorana particles, which is a spectacular breakthrough in itself, we now want to concentrate on creating a working quantum bit. We expect to achieve this in less than 3 years. The practically usable light-emitting silicon nanodiode is another exciting development that I expect in the short to medium term. This will make all-silicon optoelectronic integration possible and considerably speed up the interface between our computers, which are electronic, and the fibre optics used for the Internet.”

Shuxia: “I will carry on perfecting our perovskite solar cells. This includes not only the light absorber but also many interfaces in the devices. We need to understand the materials and their interactions better at the atomic, nano and micro scale. As we develop a greater understanding of the fundamental science, we will be able to design new strategies for technology breakthroughs. Realistically though, I think a commercially viable solar cell product based on this science is still 5 to 10 years away.”

Reinoud: “In addition to the spin structures I mentioned previously, I have also been working on creating novel magnetic nanoparticles for treating cancer. While this is still very much in the early stages, the first results are promising. The theory is that you inject these tiny particles in a fluid suspension into the cancer growth. Because cancer cells have a weak membrane, the magnetic forces cause them to collapse. I expect to make significant progress towards achieving personalised and patient-specific cancer treatment using nanoplatelets that are tuned to a specific cancer tissue during the next three years.”

TU/e is obviously recognised as a leading university in Applied Physics. Would you recommend TU/e to other academics looking for research opportunities?

Erik: “Having worked for Philips before switching to teaching and research, in Utrecht first, and later in Delft and Eindhoven, I am in a good position to make comparisons. As I said before, TU/e is one of the bestequipped and most highly respected universities in the world, and also attracts a wide range of interesting students. So I can thoroughly recommend TU/e to colleagues looking for research positions and the opportunity of teaching.”

Shuxia: “I first came to Eindhoven to study for a PhD in Chemistry and have lived in the Netherlands for about 12 years now. I chose TU/e initially because of its excellent reputation and the fact that it is very international. I have absolutely no regrets and would advise anybody looking for fundamental research opportunities to put TU/e at the top of the list.”

Reinoud: “I too have experience with other universities and very much enjoyed my time there. However, Eindhoven and TU/e have that little bit extra, particularly when it comes to cross-discipline and international collaboration.”

What unresolved question or dream inspires you?

Erik: “I truly hope that we will succeed in developing a quantum bit, however nobody really knows whether Majorana particles will deliver what they potentially promise. I would say quantum computing is still at least 10 to 20 years away in any case, even though we are moving in the right direction. By contrast, I do have high expectations of light-emitting silicon on a shorter timescale. Computers and the Internet account for about 10% of all the power consumed worldwide. If you succeed in using light instead of electronics, you can increase speed and reduce energy consumption by a factor of at least 100.”

Shuxia: “I dream of a world where we have solved the energy problem. We need to take radical action in the near future, install photovoltaic cells on every roof in the Netherlands, and elsewhere of course, make the transition to other forms of renewable energy in record time, and find a way of storing all the wind, wave and solar energy we harvest. The photovoltaic cells we have at the moment are good enough, but further reduction in cost is very much desired; we also desperately need better battery technology to store all that power. I and my colleagues will continue to focus our efforts on engineering suitable materials.”

Reinoud: “I am fascinated by the potential benefits that magnetic interaction at the nano level can have on health. And I look forward to exploring how we can use nanomagnetic engineering, such as spintronics, to develop MEMS and NEMS applications.