Coulomb blockade

Coulomb blockade is a quantum mechanical phenomenon that occurs in small conductive structures, such as small metal or semiconductor particles (quantum dots) or single-electron transistors. It is characterized by the suppression of electrical conduction due to the electrostatic repulsion between charged particles—specifically, electrons. In a typical scenario, when an electron is added to a small conductor, it experiences a Coulomb energy barrier due to the presence of other electrons already in the conductor.