A New Formulation of Electrical Linear Response Theory in an Arbitrary Magnetic Field

We develop a novel formulation of DC electrical linear response theory for a phase-coherent conductor with multiple leads valid in arbitrarily strong magnetic field and for a given impurity configuration and measuring geometry. This formulation is convenient for discussion of the quantum Hall effect and mesoscopic transport phenomena. In particular, mesoscopic phenomena arise from sensitivity to specific impurity configurations and sample geometries; an adequate understanding of such effects requires a formulation of linear response theory valid for a given system.