Location of Repository

## Conductance and polarization in quantum junctions

### Abstract

We revisit the expression for the conductance of a general nanostructure -- such as a quantum point contact -- as obtained from the linear response theory. We show that the conductance represents the strength of the Drude singularity in the conductivity $\sigma(k,k';i\omega \to 0)$. Using the equation of continuity for electric charge we obtain a formula for conductance in terms of polarization of the system. This identification can be used for direct calculation of the conductance for systems of interest even at the {\it ab-initio} level. In particular, we show that one can evaluate the conductance from calculations for a finite system without the need for special transport'' boundary conditions

Year: 2004
OAI identifier: oai:eprints.whiterose.ac.uk:4022

### Suggested articles

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.