Picture of Per Delsing
"I usually sit here in front of the fire in my favourite armchair when I’m reading and writing", says Per Delsing. Photo: Michael Nystås​​​​​​

Per Delsing: It is easier to rule an electron than raise four daughters

​A doctorate in 1990, Assistant Professor in 1991, Senior Lecturer in 1994, Professor in 1997, all by the age of 37. Per Delsing’s academic journey has moved swiftly. Now he’s heading up the billion SEK project the Wallenberg Centre for Quantum Technology (WACQT), the aim of which is to build a functioning quantum computer within twelve years. “I have worked on fundamental research for a great many years, but it’s actually only now with WACQT that applications are starting to come from it, and that industry is interested”, he says. 
Like many others, Delsing works mainly from home in these times. He receives me at his home in Landvetter. We sit down in front of the stove, which is not currently lit – it is the height of summer after all.
“I usually sit here in front of the fire in my favourite armchair when I’m reading and writing, when I’m working at home or have some free time and am taking it easy,” he says about the place he has chosen for our meeting. 

Per lives here with his wife Désirée, a language teacher. His four daughters have moved out and in the past few years Per and Désirée have had the pleasure of becoming grandparents to three grandchildren.

There is a quotation hanging in his office at Chalmers from the former US president Lyndon B Johnson: “It is easier to rule a nation than raise two daughters”.
“I can certainly sign up to that! But I’ve changed the quotation from two to four daughters and replaced “nation” by “electron”. So on my wall it states “It is easier to rule an electron than raise four daughters”. Over time I’ve added “photon” and “phonon” too, he laughs.

Picture of Per Delsing.He is Professor of Experimental Physics and Head of the Quantum Technology Laboratory (AQP) at the Department of Microtechnology and Nanoscience, MC2, at Chalmers. His research area is quantum physics with nanocomponents. It started with single-electron tunnelling.
“This research area has developed but still has many ‘golden threads’. As a doctoral student I worked on individual electrons. Early on things didn’t go well. I persevered for four years without getting anything to work and was almost ready to give up. But when we changed the material from tin and lead to aluminium, everything worked properly. The measuring equipment and everything else had already been prepared so a great many results came all at once. It was a ‘ketchup effect’!”

Per took a framed photograph of his father along with him to the photo shoot in Henrik Sandsjö’s studio at Röda Sten. Tore Delsing passed away in 2001 and was the person who opened Per’s eyes to technology and the natural sciences.
“Dad was a timber logger until one of his fingers was sawn off in an accident and he received an insurance payout as a result. Thanks to that, he was able to study and become an engineer at Stockholm Technical Institute in Stockholm. It was in the 1940s and 1950s and studying wasn’t all that common at the time,” he says.

We backtrack a few decades. Västerbotten. Way up in the countryside. A different Sweden. The firstborn son became a big brother when Per Delsing and his twin brother were born at the hospital in Umeå on 14 August 1959. 
“But I’ve actually never lived in Umeå. When Dad came and picked us up from the maternity ward, he took us to a new apartment in Lycksele. And after two and half years we moved to Malmö where I grew up,” he explains.

As a qualified engineer Tore got a job at the hydroelectric power station on the banks of the Norrland rivers. After a couple of years he gained employment at the construction company Armerad Betong (later NCC) in Malmö and took his family there. They lived in the Kronprinsen district which had long housed Malmö’s highest building.
“Yes, we had quite a long journey, but we maintained contact with our home district and spent four weeks there every summer in our holiday home, 1,500 km north. You couldn’t just nip back over a weekend,” he smiles.

When he was five the furniture van was on the go again. The family then settled down in a residential district near Bulltofta airport. Mum Ann-Marie stayed at home when the children were small, but she was a trained tailor and gradually started working as a needlework teacher. She passed away a few years ago.
How would you describe your childhood?
“I was a bit of a street fighter when I was small. And I was interested in sport, and was involved in football and swimming. Competitive swimming too for a while,” explains Per.
It was Dad Tore who inspired Per and his two brothers to understand that knowledge was both important and fun.  
“Before we went to bed in the evening when we were small, he would come in to us and we’d have a quiz. All three of us thought this was great fun. It was important to take that with you into school. I remember us watching the moon landing together. I was nine years’ old. It was one of those moments, when I knew that ‘wow, I want to work on that’!” 

At secondary school Per created a chemistry box which he supplemented with ‘more advanced things’, as he expresses it with a smile. He used these to carry out various chemical experiments.
“It was like having your own chemistry lab out in the garage. I produced gunpowder, did distillations and things like that.”
Did the garage survive?
“Yes,” laughs Per.

Per and his brother, who was two years’ older, followed one another. Both studied engineering physics at the Lund University Faculty of Engineering, and his brother even became a student guidance counsellor.
“Two years into the course he came to me and told me about an exchange with ETH in Zürich. He said: ‘Nobody has applied, wouldn’t this be something for you?’” Per explains. 
He spontaneously answered no, he was enjoying it so much in Lund, but after a while he changed his mind and submitted an application after all. This was how Per Delsing ended up moving to Zürich after almost three years in Lund, and spent the rest of his engineering studies there.
“I have never regretted it. ETH is a really good university.”

Per’s realisation that he wanted to pursue research came early on, and after the years in Zürich he wanted to continue and take a PhD. So in 1984 he sat down and wrote three letters, one to Helsingfors, one to Copenhagen and one to Tord Claeson at Chalmers. They were the three universities where research was being undertaken into superconductivity at the time.
“Tord called me as soon as he got the letter and thought I should come and meet him. I didn’t get much of a response from the others. I was offered a PhD student position at Chalmers.”

During his period of study in Lund, Per had met his future life partner Désirée. In 1984 Per moved to Gothenburg. Désirée followed one year later, and in 1987 the arrival of twins expanded the family.
“Désirée actually grew up in the Kronprinsen district in Malmö where I also lived from the age of two and a half until I was five. Without knowing it, we had lived on the same estate!”
Delsing publicly defended his doctoral thesis in 1990 with a thesis on ‘Single electron tunnelling in ultrasmall tunnel junctions’. Shortly afterwards he obtained a position as an assistant professor in the Department of Physics at the University of Gothenburg. Per stayed there for seven years before he applied to go back to Chalmers.

In 2017 it was twenty years since he had become a professor of experimental physics at Chalmers, ‘specialising in tunnelling and single electronics’ as it was described at the time.
Over the years many prizes, appointments and research grants have been bestowed upon Delsing: Wallenberg Scholar, the Swedish Research Council’s Distinguished Professor grant, the Göran Gustafsson Prize and the Gustaf Dalén Medal to name but a few. 
He is a member of the Royal Swedish Academy of Engineering Sciences (IVA), as well as the Royal Swedish Academy of Sciences (KVA) and the Royal Society of Arts and Sciences in Gothenburg (KVVS). Between 2007 and 2015 he was a member of the Nobel Committee for Physics. In 2014 he was also chair of the committee with all that it entails.
“I am of course highly delighted with all these honours. But being elected to the Nobel Committee still stands out. It was a really great job, one that I’m really proud of and pleased with.
A lot of the work on the committee is confidential, but Per explains that he was involved in and presented three Nobel prizes for Physics: Andre Geim and Konstantin Novoselov “for groundbreaking experiments regarding the two-dimensional material graphene” (2010), David Wineland and Serge Haroche “for groundbreaking experimental methods that enable measuring and manipulation of individual quantum systems” (2012) and Isamu Akasaki, Haroshi Amano and Shuji Nakamura “for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources” (2014).
“The committee normally consists of eight people who are experts in different areas so that the committee covers the entire field of physics. It is a considerable amount of work that has to be divided up between the members. As chair you also present the prize at the award ceremony,” Per explains.

As a Distinguished Professor at the VR Per Delsing has been awarded ten years’ research funding up until 2025.
“It is extremely important that you have the courage to pursue difficult subjects that may not work at all, and that wouldn’t be possible with three years’ funding.”
Being awarded an ERC Advanced Grant from the European Research Council against fierce competition also meant a lot:
“It was a major grant which was also international recognition.”

The Wallenberg-funded quantum computer investment WACQT is, of course, one of those things that Delsing is most proud about. Chalmers had the honour of hosting the centre. WACQT has two missions: to raise the level of expertise in quantum technology and to build a quantum computer. The team are working in parallel on both assignments. Since its inception in 2018, a lot has happened:
“I would like to emphasise that there are a lot of us working in the centre in different roles. We have put a great deal of effort into building up the operation. We have now employed 58 people and have entered a different phase. We have established a structure for our way of working and have got industry on board in various collaborations. It feels really good, I definitely think that progress is being made,” explains Per.
“I have worked on fundamental research for a great many years, but it’s actually only now with WACQT that applications are starting to come from it, and that industry is interested. After having worked on research which is of more academic interest, it’s really great that it’s actually turning into something that is of interest to industry and the general public.”
He also thinks that the construction of a quantum computer is going well:
“We can run certain algorithms on small processors now. It’s looking good, and we have been able to proceed with building larger processors.”

Per seems to divide his time between many different activities. Apart from being a head of division and head of the WACQT unit, he supervises eight doctoral students.
How do you manage everything?
“The simple truth is that I don’t. Nor can you run as fast when you are 60 as you did when you were 40. I’m trying to get rid of some assignments. For instance, I’m not taking on any more doctoral students.”
What do you enjoy most?
“There’s a lot that is enjoyable. I think it’s extremely enjoyable to work with really intelligent people who you can have high-level discussions with. But those eureka moments when you realise that ‘that’s how it must be’ or that we’ve found what we had sought for two years is also a wonderful feeling.”

At some points in his career Per has been involved in groundbreaking scientific breakthroughs. The first one came during his time as a doctoral student.
“I discovered single electron tunnelling oscillations. There were many others who tried to observe it, but I succeeding in being the first to do so in 1989,” he explains.
In collaboration with Yale, an experiment was carried out in which they successfully developed an ultra-fast single electron transistor. 
“We built the circuit at Chalmers and then one of my doctoral students went to Yale and carried out the experiment. It was a very important step. A great deal of my research over the next ten years was based on this transistor. We performed many interesting experiments on it, which were also published in Science and Nature.

A research breakthrough that attracted a great deal of attention was what is popularly called creating light out of a vacuum: the Dynamical Casimir Effect.
“It was an important discovery that we were the first to achieve at Chalmers,” says Per.
The results, which were published in Nature, were called a ‘milestone for which researchers have waited 40 years’, and it was ranked as the fifth greatest scientific breakthrough in the world in 2011 by the journal Physics World.

Three years later Delsing’s experimental research team succeeded, in collaboration with his colleague Göran Johansson’s theoretical group, in capturing sound from an atom, and showing that this sound can communicate with an artificial atom. This made it possible to demonstrate a quantum phenomenon with sound instead of light. A door that was previously closed to the world of quantum physics now opened.
“We could place quantum dots (artificial atoms) on a piezoelectric substrate so that it was possible to connect the atom to sound instead of light. The results were published in Science, they have been well cited and have gained many followers. There are a lot of research groups working in that direction now,” he says.

How does it feel to make such a discovery? Delsing describes it as having the hairs stand up on your arms once the realisation sinks in. Like managing to do a high jump or scoring a goal from a penalty kick in football.
“Sometimes you’re looking for something special that you either find or don’t find, but if you see it, it’s quite obvious. I remember how, as a doctoral student, late one July evening I was standing looking at a curve that was being generated on an xy printer, as it was at the time. I knew that the curve should have a little peak, and suddenly saw the printer’s stylus start to go up and then down again. ”Wow, a peak”, I thought. Within a few seconds I realised that I’d got something there."

Other times researchers stumble over something quite different from what they were looking for.
“It can take quite a while for you to understand what it was that happened and how it took place. Sometimes you find something that you didn’t expect and that’s almost more exciting.”

Text: Michael Nystås
Photo: Henrik Sandsjö
Photo of Per in his armchair: Michael Nystås



Read a recent interview with Per Delsing by writer Ingela Roos >>>

MORE ABOUT PER

Born: In Umeå on 14 August 1959.
Lives: In a house in Landvetter.
Family: Married to Désirée, a language teacher. Four grown-up daughters and three grandchildren, who are three months, six months and two years’ old (in June 2020). “It all goes so fast”.
Job: Professor of Experimental Physics at Chalmers.
Leisure interests: Tennis, skiing and swimming. Very interested in humanity and evolution. “A scientific sideline.”
Listening and reading: “Mostly non-fiction, but I’ve read most of the books written by Henning Mankell and Jan Guillou. I don’t listen to as much music as I used to, I appreciate silence more. In Zürich I could play loud music and study at the same time. I can’t do that any more. I need silence around me when I have to try and understand something. My old favourites are Genesis, Supertramp and Elton John. My taste in music has stagnated over the years.” 
Favourite place for inspiration: “My mother-in-law was born on Käringön island and we have a small holiday home there. We spend most summers on the island. I find inspiration from going out into the hills.”
Most proud about: “Apart from my children? In the scientific field, I’m most proud of having been elected to the Nobel committee. You are appointed to it because you are considered to really understand physics. It was recognition. It’s not just an appointment but it’s also highly stimulating work.”
Motivation: “An inquisitive desire to understand the natural world. On the one hand to understand why something happens in the natural world and on the other to be able to turn it round and use it in some way.”
First memory of engineering: “The moon landing.”
First memory of physics: “When I learnt what superconductivity was. For once my Dad couldn’t answer the question, but I had to find it out for myself. It was then I realised that I thought it was a really interesting and exciting subject.”
Best thing about being a researcher: “Being able to work on something that is so interesting and that you are passionate about, together with incredibly talented doctoral students and colleagues. To be entrusted with the task of developing knowledge during working hours.”
Challenges of the job: “Managing to do everything you would like to do.”
Dream for the future: “A great many of my dreams have been fulfilled. Of course, I had a dream of becoming a professor. I have also been able to achieve many of the discoveries I dreamt about. I dreamt of having grandchildren.”
Hidden talent: “I think I’m quite handy. I do quite a lot of practical work at home: carpentry, laying floors, electrical work.”

Page manager Published: Wed 09 Dec 2020.