Fröhlich model

The Fröhlich model describes how electrons interact with vibrations (phonons) in a polar crystal, like certain insulators and semiconductors. When an electron moves through such a material, it distorts the surrounding positive ions, creating a cloud of polarized vibration called a phonon. This electron-phonon coupling influences how easily the electron can move, affecting electrical conductivity. The model simplifies this complex interaction by focusing on long-range forces between electrons and lattice vibrations, providing a foundation to understand phenomena like electrical resistance and superconductivity in materials where these interactions are significant.