Leading scientists on topological insulators met in Berlin
Outstanding researchers took part in the “New Trends in Topological Insulators 2014” - workshop.
From July 7-10, 150 researchers met in Berlin to discuss recent findings in the field of topological insulators.
Topological insulators are a rather new form of quantum matter with an insulating bulk and a metallic surface created by topologically protected and spin polarized electronic states.
Outstanding researchers took part in the “New Trends in Topological Insulators 2014” - workshop, organized by Gustav Bihlmayer (Forschungszentrum Jülich) and Saskia Fischer (Humboldt University and Oliver Rader of HZB. 20 speakers had been invited for presentations, the 2012 Buckley Prize winners Shoucheng Zhang and Laurens W. Molenkamp (also Leibniz Prize 2014), Zhi-Xun Shen (Buckley prize 2011) and Yoichi Ando (2014 Inoue Prize for Science) being among them.
Breakthrough results were delivered on topics such as optical excitation, electron-photon entangled states, the role of electron correlation as well as imaging of helical edge states and Majorana fermions.
The event took place on the premises of the Berlin-Brandenburg Academy of Sciences. It has been generously supported by DFG as well as HZB.
- Fascinating archaeological find becomes a source of knowledgeThe Bavarian State Office for the Preservation of Historical Monuments (BLfD) has sent a rare artefact from the Middle Bronze Age to Berlin for examination using cutting-edge, non-destructive methods. It is a 3,400-year-old bronze sword, unearthed during archaeological excavations in Nördlingen, Swabia, in 2023. Experts have been able to determine how the hilt and blade are connected, as well as how the rare and well-preserved decorations on the pommel were made. This has provided valuable insight into the craft techniques employed in southern Germany during the Bronze Age. The BLfD used 3D computed tomography and X-ray diffraction to analyse internal stresses at the Helmholtz-Zentrum Berlin (HZB), as well as X-ray fluorescence spectroscopy at a BESSY II beamline supervised by the Bundesanstalt für Materialforschung und -prüfung (BAM).
- Element cobalt exhibits surprising propertiesThe element cobalt is considered a typical ferromagnet with no further secrets. However, an international team led by HZB researcher Dr. Jaime Sánchez-Barriga has now uncovered complex topological features in its electronic structure. Spin-resolved measurements of the band structure (spin-ARPES) at BESSY II revealed entangled energy bands that cross each other along extended paths in specific crystallographic directions, even at room temperature. As a result, cobalt can be considered as a highly tunable and unexpectedly rich topological platform, opening new perspectives for exploiting magnetic topological states in future information technologies.
- MXene for energy storage: More versatile than expectedMXene materials are promising candidates for a new energy storage technology. However, the processes by which the charge storage takes place were not yet fully understood. A team at HZB has examined, for the first time, individual MXene flakes to explore these processes in detail. Using the in situ Scanning transmission X-ray microscope 'MYSTIIC' at BESSY II, the scientists mapped the chemical states of Titanium atoms on the MXene flake surfaces. The results revealed two distinct redox reactions, depending on the electrolyte. This lays the groundwork for understanding charge transfer processes at the nanoscale and provides a basis for future research aimed at optimising pseudocapacitive energy storage devices.