Polarons are quasiparticle excitations that arise when electrons interact with lattice vibrations in a material. The word “polaron” was first used by Lev Landau in 1933 to describe an electron moving through a crystal lattice, and the concept was later developed by Sergei Migdal and Alexei Abrikosov. Polarons are important in many areas of physics, including solid-state physics, quantum electrodynamics, and chemical physics.
Polarons can be classified into two types: small polarons and large polarons. Small polarons are about the same size as an atom, while large polarons can be hundreds of times larger. Large polarons are often called “molecular polarons.”
Polarons play an important role in the electrical properties of solids. For example, they determine the electrical conductivity of some organic semiconductors and also affect the optical properties of these materials. In addition, polaronic effects have been observed in a variety of other systems, including superconductors, graphene, and quantum dots.
There is currently considerable interest in developing materials that exhibit novel polaronic effects. These materials could find applications in optoelectronics, photonics, energy storage, and sensing technologies.