Efficient and versatile spin-to-charge current conversion is crucial for the development of spintronic applications, which strongly rely on the ability to electrically generate and detect spin currents. In this context, the spin Hall effect has been widely studied in heavy metals with strong spinorbit coupling. While the high crystal symmetry in these materials limits the conversion to the orthogonal configuration, unusual configurations are expected in low symmetry transition metal dichalcogenide semimetals, which could add flexibility to the electrical injection and detection of pure spin currents. Here, we report the observation of spin-to-charge conversion in MoTe2 flakes, which are stacked in graphene lateral spin valves. We detect two distinct contributions arising from the conversion of two different spin orientations. In addition to the conventional conversion where the spin polarization is orthogonal to the charge current, we also detect a conversion where the spin polarization and the charge current are parallel. Both contributions, which could arise either from bulk spin Hall effect or surface Edelstein effect, show large efficiencies comparable to the best spin Hall metals and topological insulators. Our finding enables the simultaneous conversion of spin currents with any in-plane spin polarization in one single experimental configuration.Symmetry is a unifying principle that governs all aspects of Physics, from the model of atomic orbitals to the Landau theory of phase transitions. The physical properties of crystalline solids are also highly constrained by symmetry 1 and, in turn, as symmetry is progressively lowered through the 32 crystallographic point groups, novel transport effects emerge, such as the non-linear Hall effect 2 , the spin galvanic effect 3 and the valley magnetoelectricity 4 in non-centrosymmetric crystals, and the magnetochiral anisotropy 5 in chiral crystals. Crystal symmetry dictates also the geometry of a phenomenon that has attracted a lot of attention in recent years, the spin Hall effect (SHE) or its reciprocal effect [inverse SHE (ISHE)], which are generally observed in materials possessing strong spin-orbit coupling (SOC), and enables the interconversion between charge and spin currents. In conventional spin Hall materials, high crystal symmetry imposes that injecting a charge current density ( ) can only result in a transverse spin current density ( ) with a spin polarization ( ) orthogonal to both and (Figure 1a) 6 . SHE/ISHE are crucial effects for the electrical generation or detection of spin current, required in applications such as spin-orbit torque memories 7,8,9 and spin-based logic devices 10,11 . These applications would highly benefit from more versatile SHE/ISHE configurations which can be obtained by lifting the constraints imposed by high crystal symmetry and enabling unusual spin-to-charge conversion geometries in low-symmetry crystals 12,13,14 (Figures 1b,c).

Dirac and Weyl semimetals host exotic quasiparticles with unconventional transport properties, such as high magnetoresistance and carrier mobility. Recent years have witnessed a huge number of newly predicted topological semimetals from existing databases; however, experimental verification often lags behind such predictions. Common reasons are synthetic difficulties or the stability of predicted phases. Here, we report the synthesis of the Type-II Dirac semimetal Ir 2 In 8 S, an air-stable compound with a new structure type. This material has two Dirac crossings in its electronic structure along the Γ-Z direction of the Brillouin zone. We further show that Ir 2 In 8 S has a high electron carrier mobility of ~10,000 cm 2 /Vs at 1.8 K, and a large, non-saturating transverse magnetoresistance of ~6000% at 3.34 K in a 14 T applied field. Shubnikov de-Haas oscillations reveal several small Fermi pockets and the possibility of a nontrivial Berry phase. With its facile crystal growth, novel structure type, and striking electronic structure, Ir 2 In 8 S introduces a new material system to study topological semimetals and enable advances in the field of topological materials.

Magnetic Weyl semimetals are a newly discovered class of topological materials that may serve as a platform for exotic phenomena, such as axion insulators or the quantum anomalous Hall effect. Here, we use angle-resolved photoelectron spectroscopy and ab initio calculations to discover Weyl cones in CoS2, a ferromagnet with pyrite structure that has been long studied as a candidate for half-metallicity, which makes it an attractive material for spintronic devices. We directly observe the topological Fermi arc surface states that link the Weyl nodes, which will influence the performance of CoS2 as a spin injector by modifying its spin polarization at interfaces. In addition, we directly observe a minority-spin bulk electron pocket in the corner of the Brillouin zone, which proves that CoS2 cannot be a true half-metal.