Christopher Wilson, a physicist at Chalmers University of Technology in Gothenburg, Sweden, led one of Physics World's 2011 'breakthrough' experiments: he and his team proved that a vacuum, rather than being completely empty, contains detectable virtual particles. He explains his motivation for taking a working sabbatical at a biotechnology start-up in California.

You did your undergraduate degree at the Massachusetts Institute of Technology (MIT) in Cambridge. How did this affect your career?

I was able to attend MIT after I won a US Naval Reserve Officers Training Corps scholarship, so I was expected to go into the navy afterwards. But I realized while I was at MIT, which is a very intense place, that I would rather do science. Between the second and third years of my degree, I notified the navy that I didn't want to join. They could have drafted me, but they allowed me the option of paying back the scholarship money, which I've been doing ever since.

How has your move to Chalmers influenced your research?

I worked at Yale University in New Haven, Connecticut, for two years and then moved to Chalmers to work on a quantum computing project, ostensibly for a year. I've now been there for seven years. In Sweden, the work dynamic is hierarchical, like a company. There is a top professor who has several professors at different levels working under him or her — and younger researchers work their way up. It's a good system if you have a good boss. It gave me more time and freedom to get this one big experiment to work than I would have had in the United States.

Describe your breakthrough experiment.

When I got to Chalmers in 2004, my team started work on superconducting circuits for quantum computing. Around 2007, we realized that the work could allow us to measure the virtual photons inside a vacuum. These virtual photons are generated and annihilated in pairs. About 40 years ago, it was suggested that a mirror moving near the speed of light could capture some of these photons. The effect had never been observed, because it is very hard to move a massive object that fast. We made an electronic 'mirror' that we could effectively move at one-quarter of the speed of light using magnetic fields. This allowed us to separate the pairs, stopping them from annihilating and turning them into real photons that we could observe (C. M. Wilson et al. Nature 479, 376–379; 2011).

Could the media attention have a career benefit?

It certainly helps to put the paper in a certain light, especially for people outside our physics sub-field. For example, when applying for jobs, you are evaluated by a whole department. It can be difficult even for other types of physicists to evaluate the details of papers.

Why did you choose to take a sabbatical year at a start-up biotechnology company?

Last July, I was promoted to associate professor, which is tenured at Chalmers. In the US system, it is typical to take a sabbatical after getting tenure. Sweden doesn't follow the same timing, nor does the university pay academics to go on sabbatical, but I had planned to do it. I happened to see an ad on a job-posting site from a start-up company working on biomedical devices and proteomics. They needed someone skilled in algorithms and advanced statistical tools to analyse the enormous amount of data being generated about proteins, and I liked the people involved. It has turned out to be a good fit.

What kind of career impact do you expect the sabbatical to have?

I really wanted to do something to diversify my skills and develop some research lines that were completely my own — which can be a struggle in Europe's hierarchical system. I want to see if I can contribute algorithms to the field of proteomics. It would be pure hubris to think I could jump into biology, but I would like to find collaborators and see if I can develop a new aspect of my research.