Helmholtz Investigator Group on magnons
Dr Hebatalla Elnaggar is setting up a new Helmholtz Investigator Group at HZB. At BESSY II, the materials scientist will investigate so-called magnons in magnetic perovskite thin films. Her goal is to create the foundations for a new extremely efficient information technology. © HZB
Dr Hebatalla Elnaggar is setting up a new Helmholtz Investigator Group at HZB. At BESSY II, the materials scientist will investigate so-called magnons in magnetic perovskite thin films. The aim is to lay the foundations for future terahertz magnon technology: magnonic devices operating in the terahertz range could process data using a fraction of the energy required by the most advanced semiconductor devices, and at speeds up to a thousand times faster.
Today's semiconductor technology relies on the transport of electrically charged particles. The densely packed semiconductor devices on microchips generate a lot of unwanted heat, which must be dissipated at great expense. The energy requirements of information technology are immense and increasing steeply.
However, in principle, information could be processed without the transport of electrons. The key to this are magnetic patterns, either the spins of charged particles (spintronics) or spin waves in magnetic materials, known as magnons. Such magnons can propagate through a magnetic medium without moving particles, basically frictionless.
Dr Hebatalla Elnaggar is investigating magnetic thin films with a perovskite structure in which magnons can be detected. The materials scientist earned her doctorate from Utrecht University in the Netherlands and worked as a permanent researcher and head of a working group at Sorbonne University and the CNRS in Paris until recently.
Since october 2025 she has started establishing her own Helmholtz Investigator Group at HZB. “My research goal aligns with HZB's mission to discover new materials and advance technologies for a climate-neutral energy future. Here, I have access to BESSY II and its range of state of the art spectroscopic instruments, clean room facilities, and a high-performance computer cluster,” she says.
Helmholtz Investigator Group: Multi-magnons: A platform for next generation THz magnons
- Superconducting TES array X-ray spectrometer goes into operation at BESSY IIEurope's first and only TES-spectrometer at a synchrotron source is now in operation at BESSY II, developed within a collaboration between the HZB, the MPI-CEC (Mühlheim-an-der-Ruhr, Germany) and the NIST (Boulder CO, USA). The photon detection efficiency of the new instrument exceeds that of wavelength-dispersive X-ray emission spectrometers by a factor of 100 to 1000. It will be used to investigate the electronic properties of atomically thin layers, nanostructures and highly diluted atomic and molecular samples. The team is looking forward to receiving exciting research proposals from the user community.
- Magnon momentum microscopy: A new window into nanoscale spin-wavesAn international team lead by the Max Born Institute has developed a new type of momentum microscopy to image magnons — the quanta of collectively excited spins — directly in two-dimensional reciprocal space using soft X-rays. Measurements have taken place at BESSY II and PETRA III, first author ist the HZB physicist Steffen Wittrock. Owing to its remarkable sensitivity, simplicity, and access to nanometer-scale wavelengths, this novel technique establishes a powerful and versatile platform for exploring nonlinear magnon interactions, which are promising for future computing schemes.
- BESSY II: How intrinsic oxygen shortens the lifespan of solid-state batteriesAlthough solid-state batteries (SSBs) demonstrate high performance and are intrinsically safe, their capacity currently declines rapidly. A team from the TU Wien, Humboldt-University Berlin and HZB has now analysed a TiS₂|Li₃YCl₆ solid-state half-cell in operando at BESSY II using a special sample environment that allows for non-destructive investigation under real operating conditions. Data obtained by combination of soft and hard X-ray photoelectron spectroscopy (XPS and HAXPES) revealed a new degradation mechanism that had not previously been identified in solid-state batteries. They have gained some surprising insights, particularly regarding the harmful role played by intrinsic oxygen. This study provides valuable information for improving design and handling of such batteries.