Integrated Calendar

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.

The hypothalamo-neurohypophyseal system (HNS) is an evolutionarily conserved neuroendocrine interface through which the brain regulates body homeostasis by means of releasing neuro-hormones (i.e. oxytocin and vasopressin) from the hypothalamus to the blood circulation. The basic components of the HNS are the hypothalamic axonal projections, endothelial blood vessels and astroglial-like cells, termed pituicytes. These three tissue types converge and interact at the ventral forebrain to establish an efficient neuro-vascular interface, which allows the release of neurohormones from the brain to the periphery. In contrast to BBB-containing CNS vessels, neurohypophyseal capillaries are permeable, which enables bypassing the BBB to transfer HNS hormones and blood-borne substances between brain and circulation. I will present our recent molecular and functional analysis that revealed a new role for pituicytes, in establishing a permeable neuro-vascular conduit that bypasses the BBB.

TBA