Mika A. Sillanpää appointed as an Associate Professor in the School of Science
"I want to witness the wonders of Nature with my own eyes. It is the greatest pleasure to see this beautiful machinery at work, and observe how it can be understood starting from general logical principles. That is why I chose to become an experimental physicist."
Dr. Tech. Mika A. Sillanpää started his tenure track at the Department of Applied Physics on 1 April 2012. His position is a fixed-term Associate Professor. Sillanpää graduated as M.Sc. from Helsinki University of Technology – HUT, Department of Engineering Physics and Mathematics in 1999, and as a doctor of technology at HUT in 2005, making his thesis at the Low Temperature Laboratory (nowadays O.V. Lounasmaa laboratory, OVLL).
Implementing adolescence dream
Not always do scientists know far in advance that they will choose this career. Sillanpää, however, decided this at the age of 11, kind of: "I had written in my diary those days that I have decided to become a physicist", Sillanpää chuckles. Whatsoever how strictly this decision set Sillanpää's early career, he was keen on nature since very early childhood. "My mother says I was fascinated by watching the starry night sky before I could speak. Later, as many kids interested in sciences, I became addicted by particle physics. The appeal of first principles was high. At school I wrote an essay on my life as a particle physicist, and I was selected to read my essay in front of the school in the spring festival. My parents later thought this is serious, and organized us a private visit to the particle physics laboratory Cern".
Sillanpää chose to study at HUT because it has a long-term status as without doubt the best physics programme in Finland. Although he was still delighted by particle physics, he decided to go for slightly more applied way since that particular field might be a bit marginal to make a living.
However, Sillanpää's present research field is not any less exiting with regard to his childhood dreams. "I am interested in big questions. I want to know how macroscopic bodies can sustain features of quantum physics, usually applied only at the level of single atoms or molecules", he explains.
Quantum physics at low temperatures
In his doctor's thesis, Sillanpää made experiments on the effect of macroscopic quantum phenomena in Josephson junction devices. Since noise destroys delicate quantum features, and because temperature is a kind of noise, these experiments are made at low temperatures of about 20 milli-Kelvins. He spent the years 2005-2007 in the National Institute of Standards and Technology (NIST) in Colorado as a postdoc. There, he developed a "quantum bus" connecting superconducting quantum bits on a silicon chip. This work was selected as one of most twelve most influential discoveries in physics in 2007 by the leading physics popular science magazine.
Sillanpää, becoming interested in investigating quantum phenomena in moving nearly macroscopic objects, returned to Low Temperature Laboratory in 2007. "Same way as Josephson junctions can be prepared in a sophisticated quantum states which resemble the paradox of "Schrödinger's cat" being simultaneously dead and alive, quantum theory predicts that vibrating objects can be in two places same time. This will be extremely difficult to verify", Sillanpää describes with enthusiasm. In 2010, Sillanpää started this research at high effort, supported by the prestigious ERC Starting Grant funding. "Since the phenomena should be most prominent in small objects, we are studying micromechanical resonators, which measure some microns in size. We are not yet there, but we are approaching", he continues.
Last year, together with Pertti Hakonen's and Tero Heikkilä's research groups at OVLL, his group demonstrated the use of micromechanical resonators as an amplifier which has a high potential to reach the quantum regime. This discovery, published in the prestigious journal Nature, was reviewed also at Aalto news.
Sillanpää's work is nearly completely basic research. However, it is partially motivated by the possibility to use the macroscopic quantum states as a quantum bit (qubit) in a quantum computer in the future.
Cooperation across departmental boundaries
The selection of Sillanpää in one of the two open positions in condensed-matter tenure track professorship at the Department of Applied Physics also strengthens the contact between the O.V. Lounasmaa laboratory and the Department of Applied Physics. "My lab will stay in the OVLL. This is a really nice deal, supported by both Profs. Pertti Hakonen at the OVLL, and Matti Kaivola from the Department of Applied Physics. I can continue, without interruption, the experimental work of my group at the OVLL, and at the same time, contribute to the Department."
Sillanpää is a recognized researcher in the field. He has published 4 articles in Nature or Science, and 9 articles in other high-impact factor journals. For his contributions towards macroscopic quantum phenomena in Josephson junctions, he was awarded the International Union of Pure and Applied Physics (IUPAP) Young Scientist Prize in 2011.
"This adventure is never boring. Every day is different and unpredictable for an experimental physicist. This is simply great", Sillanpää reveals.