Dirac fermions in quasicrystalline graphene: Quasicrystal lattices, which can have rotational order but lack translational symmetry, can be used to explore electronic properties of materials between crystals and disordered solids. Ahn et al. grew graphene bilayers rotated exactly 30° that have 12-fold rotational order. Electron diffraction and microscopy confirmed the formation of quasicrystals, and angle-resolved photoemission spectroscopy revealed anomalous interlayer electronic coupling that was quasi-periodic. The millimeter-scale layers can potentially be transferred to other substrates. Science , this issue p. 782

${\mathrm{EuCd}}_2{\mathrm{As}}_2$ is a magnetic semimetal that has the potential of manifesting nontrivial electronic states, depending on its low temperature magnetic ordering. Here, we report the successful synthesis of single crystals of ${\mathrm{EuCd}}_2{\mathrm{As}}_2$ that order ferromagnetically or antiferromagnetically depending on the level of band filling, thus allowing for the use of magnetism to tune the topological properties within the same host. We explored their physical properties via magnetization, electrical transport, heat capacity, and angle-resolved photoemission spectroscopy measurements and conclude that ${\mathrm{EuCd}}_2{\mathrm{As}}_2$ is an excellent, tunable system for exploring the interplay of magnetic ordering and topology.

Ammonia is considered as an alternative fuel resource for a sustainable green future. The production of ammonia involves the electrochemical nitrogen reduction reaction (NRR), which has gained considerable attention due to its eco-friendly resources and nonharmful byproducts. Even with the manifold works on NRR, the technique has not reached the industrial scale because of the impediments of NRR electrocatalysts, and in addition, state-of-the-art electrocatalysts have not yet been discovered. In this review, first, the mechanism of the NRR, key metrics, and operational procedures for NRR electrochemistry are presented. Then, the electrocatalyst designs for efficient NRR are briefly introduced, followed by a discussion on the influence of the electrolytes that enhance NRR performance. The counterion effects of electrolytes on NRR performance and strategies for suppressing the HER by electrolyte additives are also discussed. Later, the NRR mechanisms are upgraded, and a comprehensive review of metal-N₂ batteries is provided. This review summarizes the effective methods for performing the NRR and strategies to suppress the HER on various electrocatalysts by tuning electrolytes and their additives. The review concludes by discussing the prospects of metal-N₂ batteries. Graphical Abstract