What is area law?

Area law is a mathematical law that describes the behavior of quantum entanglement in many-body systems. It states that the entanglement entropy between a subsystem and its complement in a local system scales at most as the boundary area of the subsystem, rather than the entire volume. This means that the information contained in a local system is limited and does not grow exponentially with the size of the system. The area law has important implications for the study of condensed matter physics, quantum computing, and the foundations of quantum mechanics. It is also closely related to the holographic principle in theoretical physics.