enkeltpartikkeltilstander

Enkeltpartikkeltilstander, often translated as single-particle states, are fundamental concepts in quantum mechanics, particularly in the study of many-body systems. They describe the quantum state of a single hypothetical particle within a system containing many interacting particles. Instead of trying to describe the complex, correlated state of every particle individually, the single-particle state approximation simplifies the problem by assuming that each particle can be characterized by its own set of quantum numbers, as if it were moving independently.

These states are solutions to a one-body Schrödinger equation, even though they are part of a larger many-body system. This approximation is valid in certain scenarios, such as when the interactions between particles are weak compared to their kinetic energy, or when considering the behavior of nucleons within an atomic nucleus. The concept is crucial for understanding phenomena like the shell structure of atoms and nuclei, and it forms the basis for many theoretical models in condensed matter physics and quantum chemistry. Examples of such states include electron orbitals in an atom or energy bands in a solid. The properties of the collective system are then often inferred by considering the behavior of these individual, idealized states.