Lagrange multiplier based transport theory for quantum wires

Abstract

We discuss how a Lagrange multiplier method of non-equilibrium steady state statistical mechanics can be applied to describe the electronic transport in a quantum wire. We describe a theoretical scheme using tight-binding model. The Hamiltonian of the wire is extended via a Lagrange multiplier to ``open'' the quantum system and to drive the current through it. Diagonalization of the extended Hamiltonian yields transport properties of the wire. We show that the Lagrange multiplier method is equivalent to the Landauer approach within the considered model.