Carrier-mediated optomechanical forces in semiconductor nanomembranes with coupled quantum wells

TL;DR

This paper demonstrates that electron-hole pairs in coupled quantum wells can induce optomechanical forces in nanomembranes, significantly surpassing radiation pressure, with control via electric fields, opening new avenues for quantum interfaces.

Contribution

It introduces a novel method of mediating optomechanical forces through carriers in quantum wells, achieving much larger forces than traditional radiation pressure methods.

Findings

Optically driven motion is three orders of magnitude larger than radiation pressure predictions.

The amplitude and phase of oscillations are tunable by an electric field.

Carrier lifetime tuning matches mechanical oscillation periods.

Abstract

In the majority of optomechanical experiments, the interaction between light and mechanical motion is mediated by radiation pressure, which arises from momentum transfer of reflecting photons. This is an inherently weak interaction, and optically generated carriers in semiconductors have been predicted to be the mediator of different and potentially much stronger forces. Here we demonstrate optomechanical forces induced by electron-hole pairs in coupled quantum wells embedded into a free-free nanomembrane. We identify contributions from the deformation-potential and piezoelectric coupling and observe optically driven motion about three orders of magnitude larger than expected from radiation pressure. The amplitude and phase of the driven oscillations are controlled by an applied electric field, which tunes the carrier lifetime to match the mechanical period. Our work opens perspectives for not only enhancing the optomechanical interaction in a range of experiments, but also for interfacing mechanical objects with complex macroscopic quantum objects, such as excitonic condensates.