Yu Song, Han-Chun Wu, Yong Guo
We demonstrate that the spatial Goos-H\"{a}nchen (GH) shift along an interface contributes an intrinsic component to the two-dimensional (2D) group delay in graphene. We point out that this term should be added to the widely adopted expression where only the scattering component at the interfaces is considered. We derive the relation between the group delay and dwell time and thus reveal that, the group delay can be directly observed by measuring a conductance difference in weak-field spin precession experiments. This physical observable not only implies the group delay being a relevant quantity but also provides an experimental evidence for the intrinsic effect of the GH shift. Finally, we revisit the associated Hartman effect, a central issue of the group delay, by analytically solving it via the vested relation and calculating its observable at the Dirac point.
View original:
http://arxiv.org/abs/1205.6984
No comments:
Post a Comment