A recent study has employed *ab initio* simulations to investigate the fundamental limits of tunneling in two-dimensional (2D) semiconductors. This research is crucial for understanding and optimizing the performance of transistors based on these materials, which are promising for next-generation electronics due to their scalability and energy efficiency. The work focuses on determining the intrinsic barriers to tunneling, a key quantum phenomenon in charge transport across junctions and contacts in electronic devices.

The method used, called the *ab initio* Transfer Length Method (TLM), allows for the precise calculation of contact resistances and transfer lengths in metal-2D semiconductor interfaces. Unlike empirical or semi-empirical approaches, *ab initio* simulations start from the fundamental principles of quantum mechanics, without adjustable parameters, providing a more accurate description of electronic interactions at the atomic scale. This is especially relevant in 2D systems where electronic properties are strongly influenced by atomic-level structure and composition.

The results of these simulations offer a detailed understanding of how electronic tunneling is limited by band structure and interface properties in various 2D semiconductors. This information is vital for designing devices with ultralow contact resistances, a fundamental requirement for overcoming current bottlenecks in transistor performance. The ability to predict these theoretical limits allows engineers and materials scientists to identify the most promising materials and interface configurations for future applications in high-speed and low-power electronics.