Acoustic modulation of individual nanowire quantum dots integrated into a hybrid thin-film lithium niobate photonic platform

TL;DR

This paper demonstrates the use of surface acoustic waves to modulate and tune the emission wavelengths of nanowire quantum dots integrated into a lithium niobate photonic platform, enabling spectral matching for quantum information applications.

Contribution

It introduces a scalable strain-tuning method using SAWs on a hybrid lithium niobate platform to control quantum dot emission wavelengths.

Findings

Achieved 0.70 nm wavelength modulation at 13 dBm power.

Enhanced modulation to twice the initial with an acoustic cavity.

Brought two quantum dots into resonance with a 0.5 nm initial difference.

Abstract

Surface acoustic waves (SAWs) are a powerful tool for controlling a wide range of quantum systems, particularly quantum dots (QDs) via their oscillating strain fields. The resulting energy modulation of these single photon sources can be harnessed to achieve spectral overlap between two QDs otherwise emitting at different wavelengths. In this study, we integrate InAsP/InP nanowire quantum dots onto a thin-film lithium niobate platform, a strong piezoelectric material, and embed them within Si$_{3}$N$_{4}$-loaded waveguides. We demonstrate emission wavelength modulation of 0.70 nm at 13 dBm with a single focused interdigital transducer (FIDT) operating at 400 MHz, and achieve twice this modulation by using two FIDTs as an acoustic cavity. Additionally, we bring two QDs with an initial wavelength difference of 0.5 nm into resonance using SAWs. This scalable strain-tuning approach represents a significant step towards producing indistinguishable single photons from remote emitters heterogeneously integrated on a single photonic chip, and paves the way for large scale on-chip quantum information processing using photonic platforms.