The photon trainer
In her dissertation, physicist Dr. Natasha Tomm co-developed a super-efficient source of individual photons. Her research could help make data exchange more tap-proof. The Swiss Academy of Sciences has awarded her the Prix Schläfli 2022 in physics.
17 May 2022
When she talks about it, one gets the feeling that physics is essentially a large playground in which curious, inquisitive people like her get to play every day to their hearts’ content. Naturally, this image does not accurately capture the complexity of the material with which Natasha Tomm works. At the same time, it’s also not entirely false. After all, the young woman’s passion for physics does, in fact, have something to do with playfulness and fun.
“I had a really great physics teacher who always encouraged us to ask questions. And he told a lot of jokes,” the 30-year-old explains. “I find it fascinating to study phenomena all the way down to the smallest detail until I understand them. And, once you’ve understood something, you can manipulate it in order to find a use for it.”
Tap-proof data exchange
She will now be awarded with the Prix Schläfli for this kind of “manipulation”. For her dissertation at the University of Basel, she worked to develop a source for individual photons. Photons – the smallest amounts of light – play an important role in the fields of quantum computing and data communication because they are used to transport data.
“When I send an email, it’s essentially a box filled with x number of photons,” the physicist explains. “If someone along the way steals a few of these photons, the message will still arrive and no one will notice that data was stolen.”
When data is transferred using individual photons, however, a leak can be identified immediately because the information will not arrive at its destination. Tomm and her colleagues developed a source in a semiconductor that can emit enormous quantities of individual photons – namely 1 billion per second. In this system, photons are generated by agitating an “artificial atom” – a quantum dot – that is made up of several thousand atoms.
Normally, photons would exit the quantum dot in all possible directions, meaning the majority would be lost. But the Basel-based research group was able to position the quantum dot in a “funnel” to send all the individual photons out in a certain direction and efficiently collect them for use.
“Natasha worked very hard and was extremely determined”
The Brazilian physicist had previously worked with light and optics, but her work was mainly for biomedical use. “I wanted to go back to pure physics,” she says. She applied to PhD programs around the world. She considers herself lucky that she was accepted to the program in Basel. “It was the perfect match,” she says.
When she joined the research group, the project was already very advanced. “My predecessor had done an incredible job.” And even though she repeatedly talks about “luck”, Natasha Tomm’s success is the result of hard work, as her advisor Prof. Richard J. Warburton emphasizes: “Natasha worked very hard and was extremely determined, and she took a leadership role when it came to carrying out the experiments and interpreting the results.”
She truly deserves to now reap the rewards of all her hard work. Natasha Tomm sees the award as “a lovely acknowledgement of my efforts over the years.” And, not least, it is also a recognition of her work as a woman in her field. “Winning this kind of an award in such a male-dominated environment makes it even more special for me,” she says.
Natasha Tomm’s contract with the University of Basel will expire at the end of June. Then she will leave Switzerland. She does not yet know where her career will take her. “Maybe I can use my research to found a start-up and enter the world of business.”
Her departure from Switzerland is just one of many goodbyes in her life. “Naturally, I miss my family and my home country. But I haven’t lived there since I was 17 years old,” she says. Perhaps this is why she finds it so easy to find her footing in a new place. At one point, a semester abroad took her to Leipzig. “I fell in love with Germany immediately,” she says. And when she later moved to Zurich for her master’s degree, she fell in love again, she says, laughing. “I was a poor student and everything was terribly expensive, but I still enjoyed it: the summer by the lake, the mountains.”
In Switzerland, she learned to ski and rediscovered her love of hiking. And she got to explore Europe: “I love travelling and discovering different cultures and cuisines.” And there it is again, her infectious laugh, which could easily obscure just how hard she has worked to get to where she is today. “I was a girl from a small town in Brazil – and now I’m being honored with this award. What a journey.”
The Prix Schläfli is awarded annually by the Swiss Academy of Sciences (SCNAT) to the four most important insights of young researchers at Swiss universities. The prize has been awarded since 1866. In addition to Natasha Tomm, Luca Dal Zilio (ETH Zurich), Anna-Katharina Pfitzner (University of Geneva) and Philippe Schwaller (University of Bern/IBM Research Zurich) also received the prize in 2022 for findings in their dissertations.
This text is based on a press release by SCNAT.