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Kansanen's research is related to the second quantum revolution. Its foundations are being laid right now.

The first quantum revolution was based on a deeper physical understanding of matter and its properties. This development, starting from the 1950s, has led to personal computers and smartphones, revolutionizing the way of living all around the world.

At the heart of quantum mechanics is the idea that matter has wave-like qualities. It was first thought, in the beginning of the 20th century, that as interesting as it seems, it concerns mostly the smallest elements of nature, atoms and their electrons. However, it has been shown in the last few decades that there is no size limit to quantum mechanics.

We are witnessing a race for a useful quantum computer. Such a machine is made of countless atoms. The idea is to use their shared wave-like behavior to solve problems which are difficult for our current computers. The information resides in such ``waves´´ which are then manipulated. It is aptly termed quantum computing.

There is a downside to having large systems because the wave-like qualities are easily lost. The interaction between the system and its environment leads to a loss of information. Controlling this loss is the largest challenge for quantum computers and the reason why the world doesn't appear quantum to our senses.

The destruction of quantum mechanical features poses a challenge for theory as well. It is still an active research topic in theoretical physics.

The dissertation of Kansanen gives an overview to current hybrid quantum technologies, arising from light-matter interactions. His research focuses on modelling such systems.

Interdisciplinary research at the boundary of physics and chemistry

A part of Kansanen's research is related to the quantum technology of chemistry. It focuses on a question whether chemistry can be changed by using electromagnetic vacuum fields.

In the very beginning of 20th century, it was generally thought that light travels in aether, hypothesized substance permeating the whole universe. However, the theories of aether could not correspond to experiments. Nowadays we think that light travels without any medium using electromagnetic fields. In a quantum mechanical picture, these fields exist without light, in which case they are called vacuum fields. They can nevertheless interact with matter.

This interaction is often too weak to be seen. It can be magnified by trapping the matter part and the electromagnetic vacuum field in between metallic mirrors.

The first observations on the effect of vacuum fields to chemistry are now a decade old. We don't still understand them.

"It is a damn hard problem," says Kansanen, "because you should get both chemistry and quantum mechanics of light-matter interaction. And that's where you start."

In an article still in under peer-review, Kansanen and his supervisor, professor Tero Heikkilä show that molecules undergoing a chemical reaction interact indirectly through a vacuum field. The molecules can then behave collectively. In theory, the vacuum field can slow down or even fully inhibit a chemical reaction.

"When I first understood it, I was very surprised. It really required thinking outside the box, and I wouldn't been able to do it without Tero, but now it starts to make a bit of sense,"describes Kansanen and continues:

"Our work is of course just a tiny piece of the story. At some point, it might revolutionize our understanding of chemistry."

M.Sc. Kalle Kansanen defends his doctoral dissertation ‘Open hybrid quantum systems’ on Friday 2 September at 12 noon. Opponent professor Göran Johansson (Chalmers) and Custos professor Tero Heikkilä (Ä¢¹½Ö±²¥). The doctoral dissertation is held in English.

The dissertation is published in JYU Dissertations series, number 552, Jyväskylä 2022. Link to publication: