Noise and dynamics in acoustoelectric waveguides

TL;DR

This paper develops a quantum field theoretic model for acoustoelectric waveguides, incorporating dissipation, noise, and drift effects, to analyze plasmon-phonon interactions and noise characteristics in complex geometries.

Contribution

It introduces a unified quantum framework for acoustoelectric interactions that accounts for dissipation, noise, and drift currents in arbitrary waveguide geometries.

Findings

Derived closed-form expressions for frequency shifts and noise spectra.

Showed how drift currents Doppler-shift plasmonic resonances.

Extended known results to complex geometries.

Abstract

We present a quantum field theoretic formulation of acoustoelectric interactions in waveguide-like systems of arbitrary cross-section. Building on an open quantum systems approach, we derive a unified description of plasmon-phonon coupling that incorporates dissipation, noise, and the influence of drift currents. Our analysis captures both bulk and surface plasmon modes, highlighting how drift currents Doppler-shift plasmonic resonances and reshape the phonon noise spectrum. The resulting Heisenberg-Langevin equations yield closed-form expressions for frequency shifts, gain, and noise power spectra, enabling direct evaluation of performance metrics such as the noise factor in acoustoelectric amplifiers and oscillators. In the appropriate limits, this framework reproduces known results while extending them to complex geometries.