Electronic Properties of Two Dimensional Systems

Electronic properties of two-dimensional (2D) systems, particularly in the context of 2D materials, have garnered significant attention in recent years owing to their unique and fascinating characteristics. Graphene, a single layer of carbon atoms arranged in a hexagonal lattice, serves as a paradigmatic example of a 2D material with extraordinary electronic properties. Its exceptional high carrier mobility, near-zero bandgap, and remarkable thermal conductivity have spurred research into a diverse array of 2D materials, such as transition metal dichalcogenides (TMDs), phosphorene, and black phosphorus, each exhibiting distinct electronic features. One key aspect of 2D materials is their tunable bandgap, a crucial parameter that determines their applicability in electronic devices. Unlike graphene, which lacks an intrinsic bandgap, TMDs possess a variable bandgap, making them suitable for transistor applications. The quantum confinement effect in 2D systems leads to discrete energy levels, contributing to quantum dots' formation, which holds promise for quantum computing. Furthermore, the interplay of spin and valley degrees of freedom in certain 2D materials, known as valleytronics, offers new avenues for information processing. The emergence of novel phenomena, such as the fractional quantum Hall effect and topological insulators, in 2D systems has broadened our understanding of condensed matter physics. Researchers are also exploring van der Waals heterostructures, where different 2D layers are stacked to engineer customized electronic properties. As the exploration of 2D materials continues, their electronic properties not only provide fundamental insights into condensed matter physics but also offer a rich playground for the development of next-generation electronic and optoelectronic devices with unprecedented functionalities.