excitonpolaritások

Excitonpolaritons are quasiparticles formed by the strong coupling of excitons and photons. An exciton is a bound state of an electron and a hole in a semiconductor material, representing an excited state of the material. A photon is a quantum of light. When the energy and momentum of an exciton and a photon match, they can interact very strongly, leading to a hybridization of their wavefunctions. This mixing results in two new quasiparticles, known as upper and lower polaritons.

These polaritons inherit properties from both the exciton and the photon. They possess some excitonic character, meaning they can interact with the material, and some photonic character, meaning they can travel long distances with very little scattering. This unique combination makes excitonpolaritons highly interesting for fundamental physics research and for potential technological applications.

The strong coupling regime, necessary for excitonpolariton formation, typically occurs when the interaction strength between excitons and photons exceeds their individual decay rates. This phenomenon is often observed in microcavities, where light is confined and its interaction with excitons is enhanced. The study of excitonpolaritons is relevant to fields such as Bose-Einstein condensation in solids, low-threshold lasers, and optical switching devices. Their behavior is governed by quantum electrodynamics and condensed matter physics principles.