quasiparticles

Just as particles can be described as waves through the wave-particle duality, waves can be described as particles. Quasiparticles are the quantized particles associated with various types of waves in condensed matter systems. They are similar to particles in that they have a well-defined set of quantum numbers and can be described using the same mathematical formalism as individual particles. They differ in that they are the result of the collective behavior of a physical system.