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Low-energy (∼100eV) electrons have been employed for more than half a century to investigate physical, chemical and electronic phenomena in condensed matter and surface physics. A particular role may be attributed to a purely quantum-mechanical property of the electron–its spin or intrinsic angular momentum. Since the 1970s the electron spin has been indispensable in determining the role of spin-dependent interactions, such as exchange interaction and spin-orbit coupling and their consequences. Most recently, the aspect of topology and its role in condensed matter systems has given a new drive to the investigation of the electron spin and spin textures in such materials. New results on time-dependent ultrafast phenomena may become available by the availability of new intense lasers and laser-driven sources.

It has been predicted that elemental Iron, with low dimensionality, will be a topological metal hosting Weyl nodes. Here, Chen et al. grow iron on tungsten, a heavy metal with a strong spin-orbit interaction, and using momentum microscopy, show the emergence of giant open Fermi arcs which can be shaped by varying the magnetization of the iron.

Current limitations of spintronics devices based on bulk topological materials stimulate the search for new materials and structures with interesting spin properties. Here the authors report a chiral spin texture around the Fermi level related to structural symmetry breaking in a TaSe2 layer grown on a Bi2Se3 surface.

Spintronic devices, where the spin of the electron becomes the main carrier of information, offer a promising avenue to develop quantum devices. The authors experimentally and theoretically investigate spin-polarization and spin-orbit mixing in a W(110) surface, and provide a mean to fine tune the quantum (de)coherence of materials by changing the spin polarization of a conduction electron in a spintronic device

JuSPARC, the Jülich Short-Pulsed Particle and Radiation Center, is a laser-driven facility to enable research with short-pulsed photon and particle beams to be performed at the Forschungszentrum Jülich. The conceptual design of JuSPARC is determined by a set of state-of-the-art time-resolved instruments, which are designed to address the electronic, spin, and structural states of matter and their dynamic behaviour. From these instruments and experiments JuSPARC derives the need of operating several dedicated high pulse-power laser systems at highest possible repetition rates. They serve as core units for optimized photon up-conversion techniques generating the light pulses for the respective experiments. The applications also include experiments with spin polarized particle beams, which require the use of laser-based polarized gas targets. Thus, in its rst stage JuSPARC comprises four driving laser systems, called JuSPARC_VEGA, JuSPARC_DENEB, JuSPARC_SIRIUS and JuSPARC_MIRA, which are outlined in this article.

The consequences of electron-electron interactions are difficult to calculate reliably but this is needed to understand important physical properties such as ferromagnetism. Tusche et al. show that interaction effects in cobalt are nonlocal, presenting a challenge to future theoretical approaches.

In semiconductors containing heavy elements, the Rashba spin-orbit interaction can couple the momentum and spin of electrons, yielding spintronic functionality. Here, the authors image band- and orbital-dependent spin-textures in the layered polar semiconductor BiTeI, demonstrating behaviour beyond the standard Rashba model.

The detailed electronic structure of a layered semiconductor 1T-TiS _2 and its modification in Ni-intercalated Ni _1/3 TiS _2 were studied beyond the full surface Brillouin zone by use of a momentum microscope and He-I light source on their in-situ cleaved surfaces. Clear dispersions associated with the electron Fermi surface (FS) pockets induced by the self-intercalated Ti in non-doped 1T-TiS _2 around the M points, as well as the hole FS pocket induced by the surface Ni in Ni _1/3 TiS _2 around the Γ point, were confirmed in the observed high-resolution E _B (k _x , k _y ) band cross sections. A bird’s eye view of the two-dimensional band dispersions E _B (k _x , k _y ) clarified many complex band dispersions. The experimental results are compared with first-principles band calculations performed for the bulk as well as the one monolayer (ML)-TiS _2 and surface-1ML-Ni _1/3 TiS _2 . The characteristic changes of the band dispersions near the Fermi level (E _F ) are ascribed to the contribution of the 3d states of the surface Ni atoms with the C _3v symmetry in contrast to the ‘D _3d ’ symmetry of the intercalated Ni. The importance of experimental studies of band dispersions in the full Brillouin zone is demonstrated, showing the high potential of momentum microscopy.