Researchers produce pioneering superfluidity results

Edmonton, AB November 3, 2003 Researchers in the University of Alberta department of chemistry have combined homemade equipment and a lot of brainpower to arrive at and extend the frontiers of knowledge in the field of superfluidity.

Dr Wolfgang Jaeger and his research team at the U of A are collaborating with Dr Robert McKellar’s research group at the National Research Council of Canada to conduct experiments that they say have never been done before. The results were published last month in Physical Review Letters, and a companion article about the research published in Physical Review Focus featured quotes from researchers around the world who hailed the achievement of Drs Jaeger and McKellar’s latest experiments.

In his most recent experiments, Dr Jaeger used the spectroscopy machine that was built in the U of A machine shop several years ago one of only “seven or eight” such machines in the world, Dr Jaeger says to stick individual, chilled liquid helium atoms to a nitrous oxide molecule. (With the possible exception of chilled liquid hydrogen, chilled liquid helium is the only known superfluid, meaning it is the only liquid that flows continually without friction or viscosity, although only at the microscopic level.)

Dr Jaeger is doing these experiments to try to determine the changing properties of the relationship between the atoms and the molecule as more atoms are added. He says there are currently gaps in our knowledge between how the molecule reacts with one or just a few atoms (which is known) and how it reacts with hundreds of thousands of atoms attached (which is also known).

“It’s the area between the microscopic and macroscopic levels that we don’t know about but are trying to understand,” he says. He is currently working on this problem with four PhD students, one post-doctoral fellow, and Dr Yunjie Xu, a former research associate who is now a fellow chemistry professor at the university.

The basic research is being conducted as part of a program of experiments that Drs Jaeger and McKellar have designed. There are no known applied aspects to this research, but that is only because it is an area of research that has never been explored before, Dr Jaeger adds.

“If, 50 years ago, someone said they wanted to make an investment to improve eye treatments, they probably would have given their money to eye doctors, but they would have been better off giving it to spectroscopy researchers, because their research eventually led to the development of the laser and ultimately made laser eye surgery possible,” he says, paraphrasing words often spoken by Nobel Laureate Harold Kroto.

As well as discovering how the gap in properties is bridged between the micro and macroscopic levels of chilled liquid helium, Dr Jaeger also wants to conduct the first tests to see if chilled liquid hydrogen will also show superfluid properties as researchers have predicted it will.