Theory at the service of practice

Jelena Klinovaja is happy at the University of Basel and enjoys the close collaboration with colleagues, who deal with theoretical questions or their experimental implemenation.

In February 2019, Jelena Klinovaja will become an associate professor at the University of Basel’s Department of Physics – ample reason for the SNI network to get to know the young professor and expert in condensed matter physics a little better.

Even as a child, Jelena Klinovaja was fascinated by mathematics and physics, successfully taking part in numerous contests and olympiads. However, the disconnect she often felt between mathematical concepts and the real world led her to begin studying theoretical physics at the renowned PhysTech in Moscow in 2003. In 2009, after completing her master’s degree, she moved to Basel to do a doctorate under Professor Daniel Loss, which she concluded with summa cum laude after only three years. She worked on relativistic spin-orbit coupling and superconductivity in different nanomaterials. In 2013, Jelena’s PhD thesis earned her the Swiss Physical Society Award for outstanding research in the field of condensed matter physics, endowed by IBM. After completing her dissertation, she received a scholarship from Harvard University (Cambridge, USA) to continue doing theoretical research in quantum physics of condensed matter there.

Back to Basel
For the next step in her career, an assistant professorship, Jelena had three options to choose from: University of Chicago, EPF Lausanne, and the University of Basel. “For me, a decisive factor was the excellent cooperation between theoretical research in condensed matter and outstanding experimental groups that Basel had to offer,” the young researcher said of her decision to return to Basel, to the Department of Physics as a tenure-track assistant professor in 2014.

Thanks to an ERC Starting Grant which she received in 2017, her involvement in the NCCR QSIT, and funds from the SNSF, Jelena has been able to put together a notable international team consisting of two PhD students and five postdocs. In close cooperation with the group of Daniel Loss, Jelena and her colleagues are working on topics that they hope will contribute to the development of a quantum computer. Their goal is to create memory units (Qubits) that are more resistant to external disturbances than other Qubit candidates. In pursuit of this goal, Jelena Klinovaja wrestles with theoretical predictions and calculations involving a wide range of model systems that make the work of experimental physicists more likely to succeed.

Success built on theoretical considerations
One possibility for more stable memory units involves a kind of exotic particle known as a Majorana fermion. Theoretically predicted over 70 years ago by the Italian physicist Ettore Majorana, these are particles with highly peculiar properties that make them promising candidates for a solution known as topological Qubits. However, even proving the existence of Majorana particles is difficult, and something of a lottery to begin with, as Jelena explains. Nevertheless, theoretical considerations and predictions about which materials to use in which circumstances can improve the odds of finding the particles. For example, thanks to the joint efforts of Jelena Klinovaja’s and Loss’s teams, a group led by Professor Ernst Meyer (Department of Physics, University of Basel) succeeded in devising experimental conditions in which they were able to create, observe and image Majorana fermions at the extremities of nanowires that consist of individual iron atoms.

This is precisely the kind of synergy between theory and experiment that motivated Jelena to return to Basel in the first place, and the satisfaction it gives her is plain to see. “We have outstanding experimental physicists here in the department, whom we can support with our theoretical deliberations. I am very happy to be working in such a stimulating environment,” she remarks.

Building a network
In order to have an overview of the topics the various groups are working on and to encourage discussion, Jelena organizes a weekly lunchtime seminar in which PhD students and postdocs have the opportunity to report on their research. “It is important for me as a junior member of the department to make contacts and build a network. We can learn from each other in-house in a way that would otherwise only be possible at conferences,” she explains.

This is also why Jelena Klinovaja has been a member of the SNI for two years without having taken part in a project. That said, it is only a matter of time – her theoretical research revolves around highly topical problems that must be solved along the way to a quantum computer, and are perfectly suited to projects at the SNI PhD School.