HIGH MAGNETIC FIELDS PROBE MULTIEXCITON STATES IN ORGANIC MATERIALS
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 [...]
EXPERIMENTAL OBSERVATION OF BETHE STRINGS
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 [...]
HIGH-FIELD CHARGE ORDER ACROSS THE PHASE DIAGRAM OF YBCO
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 [...]
GATE-TUNING ACROSS THE SUPERCONDUCTING DOME OF MONOLAYER WS2
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 [...]
HOW CHARGE ORDER WEAKENS SUPERCONDUCTIVITY IN YBa2Cu3Oy
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, [...]
A MULTICALORIC COOLING CYCLE THAT EXPLOITS THERMAL HYSTERESIS
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, [...]
STRONG INTERACTION EFFECTS IN MoS2 LANDAU LEVELS
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.
A DROSOPHILA FOR WEYL PHYSICS: GdPtBi
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”.
ELECTRON-HOLE TUNNELING IN MOMENTUM SPACE REVEALED BY QUANTUM OSCILLATIONS
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.
PLANCKIAN DISSIPATION IN HIGH-TC SUPERCONDUCTORS
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.