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Atomically thin van der Waals magnetic materials have gained intensive research interests in the past few years. The topic paves a way to understand the stabilization and dissipation mechanisms of long-range magnetic order in the 2D limit, which is crucial for both fundamental condensed matter physics research and technological applications. However, limited by the sample size, conventional experimental techniques such as neutron diffraction spectrum and magnetization measurements are difficult to be applied to these atomically thin materials. At the same time, electronic tunneling transport measurements have been proved to be a powerful technique in the study of 2D magnetism. Here we review the electronic tunneling transports in magnetic 2D crystals, especially the detection of the phase boundaries of 2D magnets, focusing on two-material systems, i.e. chromium halides and manganese phosphorus trisulfides. In addition, the magnetic van der Waals Josephson junctions and the spin valve devices based on the 2D magnetic metals are applied to probe 2D magnetism as well. Finally, we discuss the current challenges and perspectives of potential applications of 2D van der Waals magnetic materials.

Abstract Supercapacitors with the advantages of high power density and fast discharging rate have full applications in energy storage. However, the low energy density restricts their development. Conventional methods for improving energy density are mainly confined to doping atoms and hybridizing with other active materials. Herein, a Co3O4/g‐C3N4 p–n junction with excellent capacity is developed and its application in an all‐solid‐state flexible device is demonstrated, whose capacity and energy density are considerably enhanced by simulated solar light irradiation. Under photoirradiation, the capacity is increased by 70.6% at the maximum current density of 26.6 mA cm−2 and a power density of 16.0 kW kg−1. The energy density is enhanced from 7.5 to 12.9 Wh kg−1 with photoirradiation. The maximum energy density reaches 16.4 Wh kg−1 at a power density of 6.4 kW kg−1. It is uncovered that the lattice distortion of Co3O4, reduces defects of g‐C3N4, and the facilitated photo‐generated charge separation by the Co3O4/g‐C3N4 p–n junction all make contributions to the promoted electrochemical storage performance. This work may provide a new strategy to enhance the energy density of supercapacitors and expand the application range of photocatalytic materials.