We meet at Kemigården on a June day which will prove to be one of the hottest of the year. Some seagulls are screaming around above us. Kjell Jeppson is comfortably dressed in cotton trousers, short-sleeved shirt, vest and a straw hat. He looks relaxed.
"An advantage of being a professor emeritus is that you have no other duties, but can sit for a whole day and talk to a doctoral student," he says.
The Corona pandemic has of course affected Kjell Jeppson just like everyone else this spring. He tries to be careful to pay attention to the authorities' recommendations. Recently, he celebrated his 73rd birthday. It was a different celebration:
"When the children come with their partners, I say: Strict rules! No one enters! We keep our distance! But just like that, everyone is indoors anyway, it's hard to be careful! But we have a large terrace where we could be in the end," says Kjell.
He and the family have stayed healthy during the crisis.
"When you see the reports on TV with those who have been really sick, you think that "you do not want to be in that situation"."
Kjell has stayed away from Chalmers, where he has a workplace in the Terahertz and Millimetre Wave Laboratory in the MC2 building.
"It feels a bit empty inside, but I have had very close contact with one of the doctoral students. We have spent over three months full time writing an article on three pages! Now it is submitted for evaluation," Kjell says.
He is a man who lives in the present and does not want to dwell too much in the past, but he offers some puzzle pieces during our conversation. Born in 1947, grew up in Guldheden with parents and younger sister, then a student at Landalaskolan, then high school followed by a Master of Science degree in electrical engineering at Chalmers from 1966. An obvious choice.
"We went by tram or walked past Chalmers every day. "That's where I should start," I thought. It was always Chalmers that it came to. There was a small meetinghouse where my sister attended a dance school at the same spot where the student union building lies today."
Chalmers was an important part of Kjell's everyday life, in fact throughout his entire childhood. In high school he attended a class where 26 students out of 29 started at Chalmers eventually.
"It was quite purposeful," he says with a smile.
He describes Guldheden as a nice area to grow up in and praises the city planners:
"It was a valley with buildings on both sides, a small school, a football field that was washed every winter so we could go skating, and completely car-free," he says.
Mom was a housewife and sewed all the family's clothes. Kjell remembers how all the women in the area queued at the convenience store when the new style patterns were released every spring. New fabrics were bought, summer dresses were sewn.
"It was a little fuss. Large fabrics were laid on the table and the tissue paper was fixed on them with needles. It was a different life and a small world."
Where does your technology interest come from?
"It's probably from my father. He had trained as a high school engineer at "Chalmers lägre", and was in charge of a mechanical workshop at SKF. Dad was a pure practitioner who always built small useful things from different parts. Suddenly he had built a screwdriver! He did so with everything. There was no doubt that we would replace silencers and water pumps in the car itself. But I probably never became as practical as he," says Kjell.
In May, 50 years ago, he began his doctoral studies at the then Department of Electron Physics, more or less hand-picked by the legendary professor Torkel Wallmark. During his doctoral studies, he spent a year at Rockwell International in Los Angeles. The dissertation took place in 1977 with the thesis "Design and characterization of MIS devices". As a curiosity, it can be mentioned that the thesis's main article is still cited by other researchers 30-40 times a year.
"We speculated a little about instability in mos circuits, and were a bit out on the limb, but it turned out to be pretty good. We must have been at the forefront!"
Kjell Jeppson remained at Chalmers, now as an assistant professor, and later a senior lecturer and associate professor before being promoted to professor of microelectronics in 1996.
"Microelectronics was on the rise then, and national microelectronics programs were started. We received a large grant and were able to build an education lab, "kretslabbet". It was a milestone that allowed us to start training and get real circuits made in a technology that had been inaccessible before."
Retiring was also a milestone for Kjell. Contrary to all expectations, he was invited to be a visiting professor at Shanghai University in China.
"I spent four shorter periods in Shanghai and managed to supervise a doctoral student both on site and then remotely for a Chinese PhD. Her name is Bao Jie and she is currently a postdoc in Canada. It was a new experience to connect with young people in China," says Kjell.
What's your driving force?
"Curiosity. I was also given the opportunity to change research fields from silicon components to carbon nanotubes and graphene. Graphene has such good heat-equalizing properties. We used it to spread heat on chip surfaces and in this way get better circuits. When we had done that, we thought that you can actually make transistors of graphene. That means I'm really back to where I started, and doing the same things we did then but with significantly better tools, like laser printers instead of inky xy printers and graphs hand drawn with ruler and curve template on millimeter paper. The circle is closed."
The great leisure interest since 30 years is orienteering. Kjell and his wife travel around the world and let the locations of the races control where they end up. Some recent examples are New Zealand, Switzerland, Estonia, Latvia, Lithuania, Belarus, Hungary and Croatia. In February every year there are training camps in Portugal.
"Last year I ran 97 competitions! Now it is less races to run. We just got home from Portugal before the big shutdowns."
"The travel destinations is a little different. We do not go to the big cities but end up in Castelo de Vide or some other small border village where you can get a cup of coffee for ten crowns at a cozy café, or a glass of wine for a euro," Kjell says.
Text and photo: Michael Nystås