Hall conductance and topological invariant for open systems
arXiv:1403.4676
Abstract
The Hall conductivity given by the Kubo formula is a linear response of the quantum transverse transport to a weak electric field. It has been intensively studied for a quantum system without decoherence, but it is barely explored for systems subject to decoherence. In this paper, we develop a formalism to deal with this issue for topological insulators. The Hall conductance for a topological insulator coupled to an environment is derived, the derivation is based on a linear response theory of open system. As an application, the Hall conductance of a two-band topological insulator and a two-dimensional lattice is presented and discussed.
33 manuscript pages, 4 figures, http://www.nature.com/srep/2014/140924/srep06455/full/srep06455.html