Laura Heyderman elected Royal Society Fellow (FRS)

Today, the announcement was made that Laura Heyderman, who leads the Mesoscopic Systems Group at PSI, has been elected Fellow of the Royal Society (FRS). Laura’s nomination recognises almost 30 years of research into magnetic materials and magnetism on the nanoscale, most notably, in the field of artificial spin ice.

Laura Heyderman is best known for her breakthroughs with nanomagnets - minute bar magnets that are a few hundreds of times smaller than the width of a human hair. Her research group, shared between Paul Scherrer Institute PSI and ETH Zurich where she became full professor in 2013, use these to create elaborate structures and devices. With the help of the large research infrastructures at PSI (X-rays, muons and neutrons) they then investigate the novel phenomena that they exhibit. The tiny magnetic systems they create can have a range of technological applications, such as for computation, communication, sensors or actuators.

As a Royal Society fellow, Laura joins over 1700 of the world’s most eminent scientists, whose ranks include around 85 Nobel Laureates. “When I first heard, I was quite overcome. It’s a great honour and it meant a lot to me to share this news with my family,” she says.

Paris, chocolate and the SLS

The British/Swiss scientist’s fascination with magnetism began in Paris in 1988, when, as a University of Bristol PhD student looking forward to seeing the world, she began to work on magnetic thin films at the Centre National de la Recherche Scientifique (CNRS). After a postdoc at the University of Glasgow using electron microscopy to investigate magnetic materials, Laura was drawn to a career in industry, and worked for two years in a wire and cable company followed by two years in the confectionery company, Mars.

Although magnetism had more draw in the end than chocolate, these skills were not wasted. In 1999, Laura came to work as a postdoc at PSI in what was then the Laboratory for Micro- and Nanotechnology. Here, working on nanoimprint lithography, she could use her experience in rheology from the chocolate factory and polymers from her time in the wire and cable company.

At this time, a pervasive excitement could be felt at PSI. The Swiss Light Source SLS began experiments soon after Laura’s arrival in 2001. “The SLS made a huge difference,” says Laura. “It was clear to me that we had this powerful new facility coming up, and from my experience in industry, I knew how important it would be to look to the future and make the most of this opportunity.”

This motivation, together with a desire to return to her research roots in magnetism, led her to team up with Frithjof Nolting who was then a beamline scientist and is now head of the Laboratory for Condensed Matter in the Photon Science Division at PSI. Combining her expertise in the cleanroom with his expertise in synchrotron radiation, they began bouncing ideas off each other and experimenting with magnetic nanostructures: creating them with electron beam lithography and studying them in the new SLS.

“Laura was hugely creative with respect to patterning devices,” reminisces Frithjof. “One of Laura’s strengths was to always get things done. If she said she would do something, she would always follow up.”

Following the success of their initial research, Laura and Frithjof gradually built up their own research groups, the members of which continue to collaborate to this day. This collaboration marked the beginning of her vision to use the large research infrastructures to investigate magnetism at the nanoscale.

Artificial spin ice launches the group to success

“It all started to take off with artificial spin ice,” remembers Laura. Artificial spin ices are intricate patterns of nanomagnets on surfaces, which organise as the temperature drops in a similar way to how water forms ice crystals as it freezes. These offer a platform to discover fascinating physical phenomena, with potential applications in novel high-performance computing.

In 2006, Laura was exploring with colleagues at PSI the possibility of mimicking bulk spin systems in nanomagnets when a groundbreaking paper from an American colleague demonstrated the concept of artificial spin ice. “When I heard about this, I said ‘let’s try it!’” she recalls. This was the turning point for Laura’s group, who then dedicated themselves to creating artificial spin ices and, as she puts it, “discovering all sorts of fascinating things with the x-ray beam”.

“It was like day and night. We had the clean rooms at PSI allowing us to make them and we had an instrument – the x-ray synchrotron – allowing us to make images with very high contrast. And it’s something we’re very grateful for that we still use today,” reflects Laura.

As much as the bright light of SLS was on the horizon during Laura’s first years at PSI, today a similar anticipation surrounding SLS 2.0 is felt. One of the developments currently underway in Laura’s lab is 3D magnetic imaging. At the moment, it takes a long time to make these tomographic images. The higher flux of SLS 2.0 will enable Laura’s team to make the measurements much faster. “If we can do this a lot quicker and with a higher spatial resolution, this will drive our research forwards. So we’re very much looking forward to the upgrade,” she says.

“So many people played a part”

Following their beginnings using synchrotron light to study their nanofabricated devices, Laura and her team quickly branched out to use, in addition, many of the other large scale research facilities at PSI, notably the low energy muon facility and the Swiss Spallation Neutron Source SINQ. They have also carried out X-ray free electron laser experiments.

Her nomination as a Royal Society fellow coincides with the ten-year celebration of Laura’s research group. At a recent celebration at PSI, Laura acknowledged the various people who contributed over the years. “There were lists and lists of people: at all the different large scale facilities - X-rays, neutrons and muons; the clean rooms; a host of theorists; materials experts and many more people at PSI and ETH Zurich. We are so lucky to have all of that behind us. So many people played a part in making our group what it is today.”

Text: Paul Scherrer Institute / Miriam Arrell