It all started with Nicolas Roy's trip to Stanford. Nicolas is a PhD student in the Department of Physics and a member of the NISM and NaXys Institutes. The purpose of the visit to Stanford was to develop expertise at UNamur on a new method of simulating twisted photonic crystals, recently published by the prestigious university. Following discussions during the stay at Stanford, avenues for collaboration emerged, notably that of continuing research related to one of their publications in order to try to make a device that allows the direction of the light beam to be manipulated as efficiently and compactly as possible.  The gamble paid off, as the theoretical study predicts a device measuring 6 microns (the size of a hair)!  What's more, it is very energy efficient.  In practical terms, it could be used to track satellites, for example, without moving the transmitter or receiver, which is complicated in a photonic circuit.  Another practical application is being studied for Meta, a company that wants to reduce the size of virtual reality headsets to a simple pair of glasses... 

During his PhD, and based on a Stanford team publication entitled "Theory for Twisted Bilayer Photonic Crystal Slabs", Nicolas reproduced the simulation method and developed an analytical model of the numerical simulations. The use of these inexpensive simulations has made it possible to find the photonic structures most capable of deflecting light in a controlled manner. The analytical model, in turn, provides an explanation for what has been observed, and thus a better understanding of what's going on. In short, it opens up prospects for simpler fabrication of future devices.

The research teams collaborating on this study are working on twisted photonic crystals, i.e. two-dimensional materials formed, for example, from two superimposed and structured layers of silicon, and their interaction with light. 

In designing an analytical model, Nicolas Roy also used a theory that has been known since the 1960s: lattice networks. A lattice network is a plane diffraction network with a sawtooth profile.  In concrete terms, it resembles the roofs of old factories.  The novelty he brought to this concept is that it allows us to understand the mechanism that controls the angle of the light beam's exit thanks to the twist between the two layers. In doing so, he identified that the system acted similarly to a lattice grating. The team, using meta-models, was able to concentrate the light in a very specific direction with 90% efficiency.

What is the purpose of this type of twisted structure? To control light and ultimately create systems that can slow it down or even stop it.

This twist technique therefore opens up many unexplored possibilities in photonics by adding a degree of control over light. The researchers are continuing their work in this area, continuing their fruitful collaboration with Professor Fan's team, Stanford University.  

It looks like there's no end in sight to the twisting at the University of Namur! 

The Belgian team

• Professor Michael Lobet (UNamur, Harvard University)
• Professor Alexandre Mayer (UNamur)
• Dr Nicolas Roy (UNamur)

The American team

• Professor Shanhui Fan (Stanford University)
• Dr Beicheng Lou

The researchers thank UNamur, and more specifically the Department of Physics and the NISM Institute for funding Nicolas Roy's trip, the Institut naXys for its support in this project, the PTCI technology platform, whose supercomputers made this study possible, as well as the FNRS for funding the research mandates of Michaël Lobet and Alexandre Mayer.

• Michaël Lobet, the physicist of the invisible who makes light twist
• Following in Einstein's footsteps: old theories, new perspectives
• Publication on light observation in Nature Communications

In the picture, from left to right: (top) Pierre Louette, Director of the Physics Department; François Briard, Head of the Science Portal Group (CERN); Julien Colaux, IBA specialist, physics researcher; Boris Hespeels, biology researcher; Alexandre Mayer, physics researcher; Anne-Catherine Heuskin, physics and biophysics researcher. (bottom) André Füzfa, astrophysicist and mathematics researcher; Serge Mathot, Applied Physicist (CERN) and Michaël Lobet, physics researcher.

The love affair between CERN and UNamur goes back a long way. CERN's accelerator complex and experimental program are very different and much larger than those of UNamur's Physics Department, but the fields in which the two institutions work have much in common.

In addition, both guests have a personal history with UNamur. The Physics Department was pleased to welcome Serge Mathot, Referent Applied Physicist (CERN) and alumni of the UNamur Physics Department (1992), as well as François Briard, Group Leader Science Portal (CERN), and alumni of the UNamur Faculty of Computer Science (1994).

The activities began with a meeting between the guests, Rector Annick Castiaux, Vice-Rector for Research Carine Michiels, Physics Department Director Pierre Louette and several other members of the Physics and Biology Department. After a general presentation of the University, the participants pointed out the missions shared by both institutions: research and the transfer of technology and knowledge, service to society, scientific popularization and education and training.

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Physics lunch - CERN presentation

The physics lunch is the monthly meeting between students and members of the physics department and a professional, alumni or not, coming to explain his or her background and what he or she does on a daily basis as a physicist.

During this meeting, attended by around 80 people, François Briard and Serge Mathot presented CERN, the world's largest laboratory for particle physics. CERN's mission is to understand the most elementary particles and the laws of our universe.

At the end of the seminar, the students came away with stars in their eyes. Indeed, opportunities for internships or even first jobs at CERN are possible for physicists but also in many other fields.

Some internship programs at CERN are particularly well suited to the needs of young Belgian students.

The vast majority of physicists working with CERN (over 13,000) are in fact sent to CERN for varying periods of time by their employing national research institutes. CERN offers an exceptional opportunity to develop international experience under excellent conditions, in an environment that is unique in the world! What an inspiration for our young students!

The projet d'Action Recherche Concertée (ARC) PHOENIX aims to renew our understanding of medieval parchments and ancient coins. Artificial intelligence will be exploited to analyze the data generated by material characterization.

This joint study between the Department of Physics and the Namur Institute of Structured Matter (NISM) and the Department of History and the Institut Patrimoines, Transmissions, Héritages (PaTHs) will address questions relating to the production chain and use of these objects and materials in past societies.

At the same time, Serge Mathot presented a seminar in heritage science attended by some 50 people. In particular, he presented his research and the brand-new ELISA accelerator: a miniaturized gas pedal capable of delivering a 2 MeV proton beam used to perform real measurements at the Science Portal.

Having the opportunity to exchange views with François Briard, Group Leader of the CERN Science Portal is a rare opportunity. Comparing outreach activities has opened up new avenues, discovering and sharing approaches, assessing what works and what doesn't, depending on the target audience. A highly satisfying enrichment for the members present from Confluent des Savoirs (CDS), the University of Namur's research outreach and dissemination service.

Professor Anne-Catherine Heuskin and Dr. Boris Hespeels are currently working on the BEBLOB project, a Belspo project with ESA support, as part of the UNIVERSEH (European Space University for Earth and Humanity) alliance. They are particularly interested in its astonishing ability to withstand high doses of radiation.

Anne-Catherine Heuskin also works in radiobiology. Particles are used to irradiate cancerous cells in order to destroy their genetic material and prevent them from proliferating: this is the basis of radiotherapy and proton therapy.

The meeting confirmed the willingness of FaSEF and UNamur to get involved in coordinating the Belgian National Teacher Programme in French-speaking Belgium, which CERN intends to relaunch in 2026. Consideration was also given to other avenues for teacher training, such as CERN's forthcoming involvement in the "Salle des Pros", the training venue for the various players involved in teacher training at UNamur.

The TRAKK is Namur's creative hub supported by 3 complementary partners in the field: BEP, KIKK, and UNamur. In addition to the venue, François Briard was able to visit the ProtoLab , which bridges the gap between ideas and industry by being a decentralized research and development hub accessible to SMEs and project leaders by offering advanced support in prototyping products or services.

Graduating in law and information technology management (DGTIC) in 1994 after his bachelor's and master's degrees in computer science in 1993, François Briard works at CERN, the European Organization for Nuclear Research in Geneva, the world's largest particle physics laboratory.

During his school career, which was 100% at UNamur, he was vice-president of the Régionale namuroise and student delegate during his years as a candidate in economic and social sciences, computer science option.

Thanks to the multidisciplinary training provided at UNamur, he was able to seize several opportunities to redirect his career at CERN, where he was an information systems engineer from 1994 and then, from 2014, redirected his career until he became Group Leader of the Science Portal, which is CERN's general public communications center.

Serge Mathot obtained his doctorate in applied sciences from UNamur in 1992, following his bachelor's degree in physical sciences in 1985.

He then carried out a post-doctorate at the Joint Research Center (EU science hub) in Geel, which aims to bring together multidisciplinary skills to develop new measurement methods and tools such as reference materials.

He perfected his expertise in physical metallurgy before joining CERN in 1995 as a Referent Applied Physicist. He has worked on numerous research projects (CLOUD, MACHINA, ELISA...) and developed numerous parts for the manufacture of CERN's gas pedals.

CERN, the European Organization for Nuclear Research, is one of the world's largest and most prestigious scientific laboratories. Its vocation is fundamental physics, the discovery of the constituents and laws of the Universe. It uses highly complex scientific instruments to probe the ultimate constituents of matter: the fundamental particles. By studying what happens when these particles collide, physicists understand the laws of Nature.

The instruments used at CERN are particle gas pedals and detectors. Gas pedals carry beams of particles at high energies to collide with other beams or fixed targets. Detectors observe and record the results of these collisions.

Founded in 1954, CERN is located on either side of the French-Swiss border, near Geneva. It was one of the first organizations on a European scale and today has 25 member states, including Belgium.

This wonderful initiative is the result of a reflection on the integration of quantum chemistry courses at the University of Sfax initiated by Professors Mahmoud TRABELSI (University of Sfax and alumnus of the University of Namur), Besma HAMDI (University of Sfax) and Benoît CHAMPAGNE (University of Namur). The reflection has been matured over the last two decades, during which time several students from Pr. TRABELSI's team have stayed at Pr. CHAMPAGNE's laboratory.

The aim: to add a computational quantum chemistry component to their research into synthetic chemistry, including syntheses from biobased substances.

A PhD student in chemistry at the University of Sfax, Dhouha ABEIRA, is also involved in the project. She is doing an ERASMUS+ internship in Pr. CHAMPAGNE's laboratory to study the optical properties of molecular crystals.

Students were introduced to the calculation of reaction energies and the simulation of UV/visible absorption spectra. These two applications are typical of activities in quantum chemistry, as they are directly linked to the understanding of reaction phenomena and the development of new compounds for molecular optics.

Emphasis has also been placed on certain technical aspects of the calculations in order to train students in the development of computational protocols according to the questions addressed.

The courses were delivered by an inter-university team.

For the Department of Chemistry at the University of Namur:

• Professor Benoît CHAMPAGNE, Director of the Laboratoire de Chimie Théorique (LCT) of the Unité de Chimie Physique Théorique et Structurale (UCPTS);
• Dr. Vincent LIÉGEOIS, for remote IT support and whose suite of programs DrawSuite, a series of applications designed to provide tools for analyzing molecular structures and properties, was much appreciated;
• Frédéric WAUTELET of the Plateforme Technologique de Calcul Intensif (PTCI) for remote computing support and who has prepared a cluster (pleiades) dedicated to training.

For the University of Sfax Chemistry Department:

• The Dr. Mohamed CHELLEGUI, from the organic chemistry laboratory, for preparing practical work;
• Dhouha ABEIRA, PhD student in chemistry, for preparing practical work and assisting students from Sfax.

The teaching teams warmly thank the International Relations teams at the University of Namur and the University of Sfax for their help in setting up and monitoring the ERASMUS+ project.

Ten members of UNamur's academic and scientific staff, accompanied by the International Relations Department and the NGO FUCID, the University Forum for International Development Cooperation, took part in an exploratory mission co-organized with UCAD. The mission was part of the university's drive to strengthen partnerships with the South, by promoting exchanges, raising researchers' awareness of the issues facing the global South, and helping new projects to emerge.

For a week, several activities were organized to enable members of the delegation to discover the Senegalese university: a visit to UCAD and discovery of its issues, exchanges around the concept of "One Health", meetings between researchers, a field visit and a closing moment in the presence of institutional partners.

Catherine Linard, professor at the Faculty of Sciences, was part of the Namur delegation "Going on site and exchanging with our Senegalese colleagues is very important. It allows us to discover the wealth of their research, in fields often directly connected to realities on the ground," she explains.

Since 2015, Catherine Linard has been collaborating with UCAD, notably as part of a research and development project supported by ARES. "From this initial collaboration a number of dynamics were born. Several Senegalese PhD students have come to Belgium to pursue their research. And conversely, one of my Belgian PhD students, Camille Morlighem, who is working on the creation of malaria risk maps in Senegal, has been able to benefit from mobility grants for research stays at UCAD. We've also established teaching exchanges: I went to Dakar to give a week's training to PhD students in geography, and a fellow health geographer, Aminata Niang Diène, comes to Belgium every year to speak in one of my master's courses," continues the professor.

The delegation brought together profiles from several UNamur faculties and departments:

• Francesca Cecchet, Faculty of Science, President of the NISM (Namur Institute of Structured Matter) Research Institute and member of the (NaRILIS Namur Research Institute for Life Sciences)
• Laurent Houssiau, Faculty of Science and member of the NISM (Namur Institute of Structured Matter) Research Institute
• Charles Nicaise, Faculty of Medicine and President of the NaRILIS Research Institute (Namur Research Institute for Life Sciences)
• Denis Saint-Amand, Faculty of Philosophy and Letters and member of the NaLTT Research Institute (Namur Institute of Language, Text and Transmediality)
• Laurent Ravez, Faculties of Medicine and Science and member of the NaRILiS (Namur Research Institute for Life Sciences) and EsPhiN (Espace Philosophique de Namur)
• Anne Vermeyen, member of the Cellule bien-être animal
• Flora Musuamba, Faculty of Medicine and member of the NaRILIS Research Institute (Namur Research Institute for Life Sciences)
• Florence Georges, Faculty of Law and member of the NaDI (Namur Digital Institute)
• Nathanaël Laurent, Faculty of Science and member of the EsPhiN (Espace Philosophique de Namur)
• Catherine Linard, Faculty of Science and member of the NaRILIS (Namur Research Institute for Life Sciences) and ILEE (Institute of Life-Earth-Environment)
• Rita Rixen, Director of FUCID, the University Forum for International Development Cooperation
• Amélie Schnock, member of the International Relations Department