2D magnetic materials offer unprecedented opportunities for fundamental and applied research in spintronics and magnonics. Beyond the pioneering studies on 2D CrI 3 and Cr 2 Ge 2 Te 6 , the field has expanded to 2D antiferromagnets exhibiting different spin anisotropies and textures. Of particular interest is the layered metamagnet CrSBr, a relatively air-stable semiconductor formed by antiferromagnetically-coupled ferromagnetic layers (T c ∼150 K) that can be exfoliated down to the single-layer. It presents a complex magnetic behavior with a dynamic magnetic crossover, exhibiting a low-temperature hiddenorder below T*∼40 K. Here, the magneto-transport properties of CrSBr vertical heterostructures in the 2D limit are inspected. The results demonstrate the marked low-dimensional character of the ferromagnetic monolayer, with short-range correlations above T c and an Ising-type in-plane anisotropy, being the spins spontaneously aligned along the easy axis b below T c . By applying moderate magnetic fields along a and c axes, a spin-reorientation occurs, leading to a magnetoresistance enhancement below T*. In multilayers, a spin-valve behavior is observed, with negative magnetoresistance strongly enhanced along the three directions below T*. These results show that CrSBr monolayer/bilayer provides an ideal platform for studying and controlling field-induced phenomena in two-dimensions, offering new insights regarding 2D magnets and their integration into vertical spintronic devices.

Van der Waals heterostructures (vdWHs) provide the possibility of engineering new materials with emergent functionalities that are not accessible in another way. These heterostructures are formed by assembling layers of different materials used as building blocks. Beyond inorganic 2D crystals, layered molecular materials remain still rather unexplored, with only few examples regarding their isolation as atomically thin layers. Here, the family of van der Waals heterostructures is enlarged by introducing a molecular building block able to produce strain: the so‐called spin‐crossover (SCO). In these metal–organic materials, a spin transition can be induced by applying external stimuli like light, temperature, pressure, or an electric field. In particular, smart vdWHs are prepared in which the electronic and optical properties of the 2D material (graphene and WSe2) are clearly switched by the strain concomitant to the spin transition. These molecular/inorganic vdWHs represent the deterministic incorporation of bistable molecular layers with other 2D crystals of interest in the emergent fields of straintronics and band engineering in low‐dimensional materials.

Due to their anisotropy, layered materials are excellent candidates for studying the interplay between the in-plane and out-of-plane entanglement in strongly correlated systems. A relevant example is provided by 1T-TaS 2 , which exhibits a multifaceted electronic and magnetic scenario due to the existence of several charge density wave (CDW) configurations. It includes quantum hidden phases, superconductivity and exotic quantum spin liquid (QSL) states, which are highly dependent on the out-of-plane stacking of the CDW. In this system, the interlayer stacking of the CDW is crucial for interpreting the underlying electronic and magnetic phase diagram. Here, atomically thin-layers of 1T-TaS 2 are integrated in vertical van der Waals heterostructures based on few-layers graphene contacts and their electrical transport properties are measured. Different activation energies in the conductance and a gap at the Fermi level are clearly observed. Our experimental findings are supported by fully self-consistent DFT+U calculations, which evidence the presence of an energy gap in the few-layer limit, not necessarily coming from the formation of out-of-plane spin-paired bilayers at low temperatures, as previously proposed for the bulk. These results highlight dimensionality as a key effect for understanding quantum materials as 1T-TaS 2 , enabling the possible experimental realization of low-dimensional QSLs.

Van der Waals heterostructures (vdWHs) allow the assembly of high‐crystalline 2D materials in order to explore dimensionality effects in strongly correlated systems and the emergence of potential new physical scenarios. In this work, the feasibility of integrating 2D materials in‐between 2D superconductors is illustrated. In particular, the fabrication and electrical characterization of vertical vdWHs based on air‐unstable atomically‐thin transition metal dichalcogenides formed by NbSe2/TaS2/NbSe2 stacks, with TaS2 being the insulator 1T‐TaS2 or the metal 2H‐TaS2, is presented. Phase transitions as 1T‐TaS2 charge density wave and NbSe2 superconductivity are detected. An enhancement of the vdWH resistance due to Andreev reflections is observed below the superconducting transition temperature of the NbSe2 flakes. Moreover, in the NbSe2 superconducting state, the field and temperature dependence of the normalized conductance is analyzed within the Dynes’ model and the overall behavior is consistent with the Bardeen–Cooper–Schrieffer theory. This vdWH approach can be extended to other 2D materials, such as 2D magnets or topological insulators, with the aim of exploring the new emergent properties that may arise from such combinations.