Leah Weiss, Sam Bayliss, University of Cambridge and Paulina Plochochka, LNCMI-Toulouse.  Intermolecular coupling plays a key role in charge transport and excited-state dynamics in organic systems. A key example of the influence of intermolecular interactions is the process of singlet fission, which involves the production of two triplet excitons [...]

Zhe Wang, HZDR Dresden and A. Loidl, University of Augsburg.  In his seminal work entitled “Eigenwerte und Eigenfunktionen der linearen Atomkette” (eigenvalues and eigenfunctions of a linear chain of atoms), published in 1931 in “Zeitschrift für Physik”, Hans Bethe succeeded in finding an exact solution to the one dimensional [...]

F. Laliberté, M. Frachet, S. Benhabib, B. Borgnic, C. Proust, D. LeBoeuf, LNCMI-Toulouse.  In hole-doped cuprates there is now compelling evidence that inside the pseudogap phase, a charge density wave (CDW) breaks translational symmetry. In YBa2Cu3Oy (YBCO) this CDW emerges in two steps: a two-dimensional (2D) order found at [...]

J. Lu, Peking University and J. Ye, University of Groningen and I. Leermakers, N. Hussey, U. Zeitler, HFML-Nijmegen. Compared with three-dimensional superconductors, atomically thin superconductors are expected to be easier to engineer for electronic applications. In this project, researchers from University of Groningen (Netherlands) together with colleagues from HFML [...]

Marc-Henri Julien, LNCMI Grenoble. The upper critical field, Hc2, is a fundamental, and technologically important property that measures the ability of a superconductor to withstand magnetic fields. Recently, there has been a controversy regarding Hc2 values in high-Tc copper-oxides, particularly in the context of the competition between superconductivity and [...]

T. Gottschall, HLD Dresden. The giant magnetocaloric effect, in which large thermal changes are induced in a material on the application of a magnetic field, can be used for refrigeration applications. However, commercial uptake is limited. Researchers from Barcelona, Darmstadt, and the HLD proposed an approach to magnetic cooling [...]

Jiangxiazi Lin, Ning Wang, Hong Kong University of Science and Technology and Benjamin Piot, LNCMI-Grenoble. Semiconducting two-dimensional transition-metal dichalcogenides (TMDCs) have been a recent hot research topic in physics, for their novel optical/electronic properties and potential applications.

C. Shekhar, MPI CPfS Dresden and Y. Skourski, HLD Dresden. In 1929, Hermann Weyl discovered that massless spin-1/2 particles are solutions of the Dirac equation. After many decades, these Weyl particles were finally experimentally revealed in 2015 in simple semimetallic materials such as TaAs. Weyl fermions are low-energy quasiparticle excitations in the vicinity of the unavoidable touching points of a valence band and a conduction band: these materials are “Weyl semimetals”.

M. van Delft, S. Pezzini, T. Khouri, C. Müller, N. Hussey, S. Wiedmann, HFML Nijmegen. Researchers from Germany, USA, UK, and the HFML Nijmegen have found evidence for electron-hole tunneling in momentum space in the nodal-line semimetal HfSiS. This specific tunneling phenomenon is revealed in quantum oscillations of the electrical resistance at low temperatures and in high magnetic fields, and can be illustrated as a ‘figure-of-eight orbit’ enclosing one electron and one hole pocket.

Cyril Proust, LNCMI-Toulouse and Louis Taillefer, University of Sherbrooke. Measuring the electrical resistance of a new material is often the first experiment that researchers do, but also often the last to be understood. Nevertheless, the temperature dependence of the electrical resistance gives essential information on the ground state of materials.