Friedel oscillations in quantum wires : interplay of interac - tions and non - equilibrium —

We discuss the electron density oscillations in an interacting onedimensional electron system with an impurity [1]. Under appropriate conditions the wave vector is given by different values kF = kL/R on left/right side of the scatterer, leading to a Landauer dipole formation. While in the non-interacting system the Friedel oscillations possess only one periodicity related to the local kL on the left side, the interplay of the interactions and non-equilibrium effects generates an additional peak in the spectrum of density oscillations at kR. The position and shape of this spectral feature, which in coordinate space is observable as a beating pattern in the Friedel oscillations, reveals many important details about the nature of interactions. We believe that it has a potential to become an investigation tool in condensed matter physics. [1] D.F.Urban and A.Komnik, Phys. Rev. Lett. 100, 146602 (2008)