Interaction-induced beats of Friedel oscillations in quantum wires

TL;DR

This paper studies how electron interactions in quantum wires cause unique beating patterns in Friedel oscillations, revealing interaction details through spectral analysis of density oscillations.

Contribution

It demonstrates that interactions induce additional spectral peaks in Friedel oscillations, leading to observable beating patterns that serve as probes for electron correlations.

Findings

Interaction induces additional spectral peaks in density oscillations.

Beating patterns in Friedel oscillations reveal interaction effects.

Spectral features can be used as tools to investigate electron correlations.

Abstract

We analyze the spectrum of electron density oscillations in an interacting one-dimensional electron system with an impurity. The system's inhomogeneity is characterized by different values of Fermi wave vectors $k_F=k_{L/R}$ on left/right side of the scatterer, leading to a Landauer dipole formation. We demonstrate, that while in the noninteracting system the Friedel oscillations possess only one periodicity related to the local $k_F$, say $k_L$ on the left side, the interplay of the interactions and the Landauer dipole generates an additional peak in the spectrum of density oscillations at the counterpart $k_R$. Being only present in correlated systems, 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. Thus it has a potential to become an investigation tool in condensed matter physics.