Gap theory of rectification in ballistic three-terminal conductors

We introduce a model for rectification in three-terminal ballistic conductors, where the central connecting node is modeled as a chaotic cavity. For bias voltages comparable to the Fermi energy, a strong nonlinearity is created by the opening of a gap in the transport window. Both noninteracting cavity electrons at arbitrary temperature as well as the hot-electron regime are considered. Charging effects are treated within the transmission formalism using a self-consistent analysis. The conductance of the third lead in a voltage probe configuration is varied to also model inelastic effects. We find that the basic transport features are insensitive to all of these changes, indicating that the nonlinearity is robust and well suited to applications such as current rectification in ballistic systems. Our findings are in broad agreement with several recent experiments.