title: Definition of current density in the presence of a non-local potential.
abstract: In the presence of a non-local potential arising from electron-electron interaction, the conventional definition of current density J(c) = (e/2m)([(p-eA)ψ](*)ψ-ψ(*)[(p-eA)ψ]) cannot satisfy the condition of current conservation, i.e., [Formula: see text] in the steady state. In order to solve this problem, we give a new definition of current density including the contribution due to the non-local potential. We show that the current calculated based on the new definition of current density conserves the current and is the same as that obtained from the Landauer-Büttiker formula. Examples are given to demonstrate our results.
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, Anhui, People's Republic of China.
authors.forename: Changsheng
authors.initials: C
authors.lastname: Li
authors.forename: Langhui
authors.initials: L
authors.lastname: Wan
authors.forename: Yadong
authors.initials: Y
authors.lastname: Wei
authors.forename: Jian
authors.initials: J
authors.lastname: Wang