Roberta Sessoli – The Convergence of the Sciences

You are a renowned chemist. What made you want to pursue this field? 

During an open day I attended, I had the opportunity to speak with a professor who convinced me to pursue Chemistry. According to her, it was a discipline in which there were more questions to ask than answers to give. I am naturally curious, and I have always been fascinated by open questions. 

Today, when people ask me for advice about choosing what to study, I always answer very simply: “Do you prefer solving problems or discovering problems?” For me, it is rather the second option. 

How did you start working on magnetism? 

I became interested in it during my second year at university. I had the opportunity to work on paramagnetic systems with my mentor, Dante Gatteschi. These materials have the particular property of developing a small magnetization in the presence of a magnetic field, although this magnetization is not permanent. 

At the beginning of my career, I discovered that some molecules could behave like small magnets. This is what is known as a single-molecule magnet (SMM). The interest of these materials lies in the fact that, when a magnetic field is applied to these molecules, they become magnetized and then take a very long time to return to their equilibrium state once the magnetic field is removed. This is referred to as slow relaxation time. This property makes it possible to store magnetic information for long periods of time. 

What were the implications of this discovery? 

At the time, physicists were investigating these types of effects, but they worked mainly with iron oxides, which had to be ordered—primarily in crystalline structures—in order for these effects to be observed. 

The magnetic properties of molecules are essentially defined by their chemical structure, which can be modulated more easily than the structure of inorganic solids. I therefore tried to draw the attention of various professors to this discovery, but it was difficult for me to gain their interest because I was a woman, I was young, and I was a chemist. I eventually had the opportunity to meet Professor Jacques Villain, a very well-known French theoretical physicist. He became fascinated by SMMs, and we began working together. Thanks to his interest in my research, other physicists also began looking into SMMs. 

You are also currently working on chirality. What is this phenomenon, and why is it interesting for your research? 

Through a project funded by the European Research Council (ERC), we recently started working on a phenomenon called chirality-induced spin selectivity. 

Chirality is a fundamental property of objects that cannot be superimposed on their mirror image. A chiral molecule therefore exists in two forms, called enantiomers, which are mirror images of one another and consequently cannot be superimposed. 

Spin, meanwhile, is a quantum property of a particle that gives it an intrinsic magnetic moment and, in simple terms, makes it behave like a small magnet. 

When electrons emerge from a chiral medium after passing through it, their spins are predominantly oriented in a particular direction, depending on which enantiomer was used to create the chiral medium. 

This is particularly interesting for applications such as oxygen production, artificial photosynthesis, and even the development of electrochemical systems. We use it to transform spin information into an electrical signal (spin-to-charge conversion). This makes it easier to detect the spin state of molecules by monitoring the electrical current. This is one of the main objectives of our ERC project, but it requires a multidisciplinary approach. To achieve this, we are working as a team with four partners, bringing together physicists and chemists in order to combine all the necessary expertise. 

Has being a woman influenced your career in research? 

At the beginning of my career, I encountered some difficulties in establishing myself in a field that was not originally mine and that was largely dominated by men. 

The only thing that can prevent us from building a successful professional career is imposing a mental burden on ourselves. Some women sometimes feel guilty when they are at work because they feel they are not present enough for their children, or conversely, that they are not sufficiently present at work. This is a pressure I refused to submit to by establishing, from the very beginning, a clear boundary between these two parts of my life. 

What message would you like to give to young people who are considering a career in science? 

First of all, it is important to have confidence in the future rather than trying to control it. Instability is part of life. I am thinking in particular of the day when I had to defend my PhD thesis in Rome with my seven-day-old child. Nevertheless, this did not frighten me because I know that there is a solution to every problem. 

Secondly, we should not forget that the most sincere motivation, and therefore the most enduring one, is to follow our own ideas. External recognition does not matter as long as our inner motivation remains strong. 

Finally, we must remain open-minded and never be afraid of change. Whether it is the people around us, the tools we use, or our opinions, everything can evolve. The important thing is to remain flexible and curious so that we never close ourselves off from new opportunities. 

Interview by Léa Ciparisse, UNamur, February 12, 2026. 

Their mission is to support and develop curiosity-driven research in Physics, Chemistry, and related fields, with the aim of “broadening and deepening our understanding of natural phenomena.” 

“2025 was the International Year of Quantum Science and Technology. Receiving the Solvay International Chair is a responsibility, especially for me, because it is the Solvay Chair in Chemistry, and I do not really consider myself a ‘true’ chemist, in the sense that I work somewhat at the interface between chemistry and physics. But I am convinced that, even though I do not work on the major research themes that currently dominate the field—catalysis, batteries, or CO₂ capture, which are very much in vogue—there are other areas in which Chemistry can play a role.” 

Roberta Sessoli, February 2026.

Using numerical simulation methods, his research allows him to investigate these properties at the molecular and even atomic scale. 

His research has numerous applications, from a technological perspective (OLED TVs and smartphone displays), to energy (photovoltaic cells and lighting panels), healthcare (monitoring devices and biosensors), and, more recently, quantum information (molecular qubits, quantum computing, and quantum cryptography). 

In addition to being a member of the Departments of Chemistry and Physics, he is also a member of the NISM Research Institute, where he has strengthened its multidisciplinary team of researchers working on the synthesis and functionalization of molecular systems and novel materials (from 0D to 3D), the design of solids with specific architectures, their surface properties, and the development of advanced techniques for studying their physicochemical properties.