Current profiles and semilocal Green´s functions in quantum magnetotransport

The study of current profiles in the two-dimensional electron gas in strong magnetic fields is central for a microscopic interpretation of the integer quantum Hall effect. Within the framework of the nonequilibrium Keldysh-Green´s function formalism, we consider the general expressions of energy-resolved and space-resolved current distributions in Hall samples. Formal elaboration, corroborated also by numerical calculations, shows that chirality of current flow, thermodynamic equilibration of conductive channels, as well as conductance quantization, are all a straight consequence of the semilocal nature of retarded (or advanced) Green´s functions in strong magnetic fields.