Highlights

It is not often that materials science ventures into the territory of particle physics — but with the study of Weyl semimetals, it does. In Weyl semimetals, energy bands cross at pairs of points at the Fermi level, and the low-energy excitations near these crossing points fulfil the Weyl equation. In other words, thanks to their unusual band topology, Weyl semimetals realize Weyl fermions as quasiparticles. This is exciting news for fundamental physics: Weyl fermions have been predicted in 1929 but remain elusive in high energy experiments. Weyl semi-metals allow us to study these fundamental particles and their exotic physics in condensed matter.

With the help of artificial intelligence, MARVEL chemists from the group of Prof. Anatole von Lilienfeld at the University of Basel have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. 

A team of MARVEL researchers of both the group of Prof. Oleg Yazyev at EPFL and the group of Prof. Matthias Troyer at ETHZ have predicted the existence of Weyl fermions in two Weyl semimetals, molybdenum diphosphide and tungsten diphosphide. The scientists used a high-throughput computational method screening a large database of existing materials, performing electronic-structure computations for each candidate.

The Weyl fermion, just discovered in the past year, moves through materials practically without resistance. Now MARVEL researchers at PSI (group of Ming Shi) and EPFL (group of Oleg Yazyev) are showing how it could be put to use in electronic components. 

MARVEL researchers in the group of Professor Oleg V. Yazyev at the Institute of Theoretical Physics of EPFL have theoretically predicted and experimentally confirmed, the  topological insulator behaviour of the beta-phase of  the  quasi-one-dimensional bismuth iodide, Bi4I4.

A team of researchers of Professor Matthias Troyer, group leader in MARVEL, and professor for Computational Physics at the Institute for Theoretical Physics at ETH Zurich, propose the existence of a previously overlooked type of Weyl fermion.

For the first time ever, MARVEL researchers in the group of Clémence Corminboeuf at EPFL used volcano plots – normally used in heterogeneous catalysis research – to study homogeneous catalysis.

MARVEL researchers in the group of Nicola Marzari at EPFL have shed new light on the fundamental mechanisms of heat dissipation in graphene and other two-dimensional materials. They have shown that heat can propagate as a wave over very long distances. This is key information for engineering the electronics of tomorrow.