Integrated Calendar

The nano-impact technique is among the latest and most considerable advances in electrochemistry and enables the detection and characterisation of individual nanoparticles, viruses, and bacteria. Its significance particularly arises from the broad applicability and simplicity of the experimental set-up and procedure: An electrode is set in contact with a solution comprising a suspension of analyte particles and is biased versus the solution potential. By virtue of Brownian motion, individual analyte entities then stochastically impact on the electrode surface, where they give rise to transient currents, Faradaic or capacitive, and an analysis provides insight into the nature of the impacting entity as well as the prevalent reaction mechanism.
The talk commences with a broad overview of the nano-impact technique while particularly theoretical aspects are highlighted. We then turn to examples of theoretical work on stochastic processes and the feasibility of individual enzyme detection to illustrate topics that are currently researched. In the light of recent developments, the talk finally points out future challenges and opportunities in the theory of nano-impacts.

Topology a mathematical concept became recently a hot topic in condensed matter physics and materials science. One important criteria for the identification of topological material is the band inversion and the crystal symmetry. In my talkI focus on new topological semimetals: Weyl semimetals. Binary phoshides are the ideal material class for a systematic study of Weyl physics. Weyl points, a new class of topological phases was also predicted in NbP, NbAs. TaP, MoP and WP2. In NbP micro-wires we have observed the chiral anomaly but NbP has served also as a model system for astrophysics: realizing the gravitational anomaly in NbP and the hydrodynamic flow of electrons in WP2. MoP and WP2 show exceptional properties such as high conductivity higher than copper, high mobilties and a high magneto-resistance effect. In magnetic materials, the Berry curvature measured via the classical anomalous Hall effect helps to identify interesting candidates for magnetic topological materials and devices. In this talk, we discuss ARPES evidence for a general theme of high temperature superconductivity - cooperative enhancement and positive feedback loop of different interactions exemplified by electron-electron and electron-phonon interactions. The accumulated evidence comes from an expanded version of angle-resolved photoemission spectroscopy and its match to in-situ material synthesis. In such experiments, the precision measurements of electron’s energy, momentum and time dynamics provide evidence for cooperative interactions as a pathway to increase the superconducting transition temperature. An outlook for ARPES development and application for other quantum materials will also be discussed.