Probing confined phonon modes by transport through a nanowire double quantum dot

TL;DR

This paper demonstrates how current spectroscopy in a nanowire double quantum dot can be used to probe confined phonon modes, revealing discrete spectral features influenced by quantum confinement and piezoelectric coupling.

Contribution

It introduces a method to experimentally probe confined phonon modes via transport measurements in nanowire quantum dots, supported by theoretical modeling.

Findings

Discrete peak structures observed in current spectroscopy.

Piezoelectric coupling significantly affects phonon mode spectrum.

Theoretical modeling matches experimental spectral features.

Abstract

Strong radial confinement in semiconductor nanowires leads to modified electronic and phononic energy spectra. We analyze the current response to the interplay between quantum confinement effects of the electron and phonon systems in a gate-defined double quantum dot in a semiconductor nanowire. We show that current spectroscopy of inelastic transitions between the two quantum dots can be used as an experimental probe of the confined phonon environment. The resulting discrete peak structure in the measurements is explained by theoretical modeling of the confined phonon mode spectrum, where the piezoelectric coupling is of crucial importance.