Quantum point contacts in magnetic fields

A method is described for the numerical calculations of the ballistic conductance in mesoscopic structures in magnetic fields within a lattice model. Examples of calculated results are given for the conductance across a single quantum point contact and a series of two quantum point contacts. The conductance is quantized even when the confinement is not adiabatic and interchannel scatterings are still appreciable. The quantization becomes better in magnetic fields. In a series of two quantum point contacts, the magnetic field dependence of the conductance is strongly dependent on the channel number of both emitter and collector contacts.