quasiparticles

Quasiparticles are collective excitations that behave like particles within a medium, such as solids or liquids. They arise from interactions among many particles, allowing us to understand complex phenomena in a simplified way. For example, in a superconductor, the interaction of electrons can create a quasiparticle known as a Cooper pair, which enables zero electrical resistance. Quasiparticles are essential in condensed matter physics, helping scientists explain properties like conductivity, magnetism, and phase transitions without needing to analyze every individual particle. They're not real particles, but they provide a useful framework for understanding complex systems.