Tunneling-Assisted Acoustic Plasmon-Quasiparticle Excitation Resonances in Coupled Q1D Electron Gases

TL;DR

This paper demonstrates that weak tunneling between coupled quantum wires causes splitting and gap formation in acoustic plasmon modes, revealing tunneling-assisted resonances that can be observed via inelastic light scattering.

Contribution

It introduces the concept of tunneling-assisted acoustic plasmon-quasiparticle excitation resonances in coupled quantum wires, a novel mechanism affecting plasmon dispersion.

Findings

Tunneling causes splitting of the acoustic plasmon mode.

Gaps open in the plasmon dispersion near quasiparticle excitation frequencies.

Resonances can be detected through inelastic light scattering.

Abstract

We show that a weak non-resonant tunneling between two quantum wires leads to splitting of the acoustic plasmon mode at finite wavevector. Two gaps open up in the dipersion of the acoustic plasmon mode when its frequency is close to the frequencies of the quasiparticle excitations. In contrast to the Laudau damping of the collective excitations, these gaps are attributed to tunneling assisted acoustic plasmon-quasiparticle excitation resonances. We predict that such a resonance can be observed in inelastic light scattering spectrum.